8x sealed Maelstrom 18s build thread - Page 4 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #91 of 784 Old 12-30-2010, 05:37 PM
Member
 
Krbass's Avatar
 
Join Date: Feb 2010
Location: Finger Lakes
Posts: 187
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I am in the same boat you are. I have 2 THTs and Really want something that goes much lower. I am considering 2 dual opposed Mal-x 18s.

I am really looking forward to this build
Krbass is offline  
Sponsored Links
Advertisement
 
post #92 of 784 Old 12-30-2010, 05:52 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by Krbass View Post

I am in the same boat you are. I have 2 THTs and Really want something that goes much lower. I am considering 2 dual opposed Mal-x 18s.

I am really looking forward to this build

dual THTs lacking lows?
kryptonitewhite is offline  
post #93 of 784 Old 12-30-2010, 06:52 PM
Advanced Member
 
DL86's Avatar
 
Join Date: Jan 2006
Posts: 537
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
I am set on building dual mal-18's in a ported 650L cab after I get my two tall auto tubas finished.

To improve the black level performance of your projector: Shine bright light into your eyes every 5 minutes.
DL86 is offline  
post #94 of 784 Old 12-30-2010, 07:03 PM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by kryptonitewhite View Post

dual THTs lacking lows?

Compared to 8-18" M-X XBL2? No contest. There ain't no horn in any numbers on this planet that will best 8 Maels below 20Hz and fit in his house.

This system is able to leap tall buildings in a single bound. I've had 8x15" Tumult MKIIs with dual MA 5050 amps and/or dual American Audio V6001 amps with the Marchand Bassis for signal shaping.

This 8x18" system is capable of 4-6dB more output below 20 Hz, depending on how the boxes fit the room.

My new system is the stackable very small system designed to use a corner, pack a serious punch and only take up 2.7 square feet per stack. Right now I have dual 3/4 stacks (3-modules with dual opposed 15s in each times 2= 12-15s). Each stack is powered by a 9kw burst-capable digital SMPS amp, each plugged into a dedicated 30A home run. The signal shaping is handled by the new piece I designed and Phil built for me.

It sounds like nothing I've ever heard. Stupid clean, flat in-room to 4 Hz and limitless output in my room.

This 8xMael-X system with dual Marathons will edge out my dual 3/4 stacks below 20Hz, which I can't even imagine. OK, check that... I can definitely imagine it. It might be able to cause a tear in space/time and we'll never hear from notnyt again.

Can't wait to read all about it.

Nice score on the amps. Karaoke equipment dot com has advertised $650 per for a long time, but I don't know anyone who actually took delivery from them off hand. They still show back order.

Get some 20 or 25A fuses and keep them on hand. I've popped several in pushing the Tumults to the limits with WOTW and 6Hz sine waves. The amp is the best bang for buck I've ever used. I'll be interested in your comments.

One of my guys talked to the owner several times a while back. He said he was having the amp up fitted with some new parts (sounds vague to me), which is what supposedly caused the delay in this last shipment. Could be a stall or could be a real change, or could be they never did ship and you're getting some of the last shipment that someone was sitting on? LMK what happens with them.

Bosso
bossobass is offline  
post #95 of 784 Old 12-30-2010, 08:39 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by bossobass View Post

Compared to 8-18" M-X XBL2? No contest. There ain't no horn in any numbers on this planet that will best 8 Maels below 20Hz and fit in his house.

This system is able to leap tall buildings in a single bound. I've had 8x15" Tumult MKIIs with dual MA 5050 amps and/or dual American Audio V6001 amps with the Marchand Bassis for signal shaping.

This 8x18" system is capable of 4-6dB more output below 20 Hz, depending on how the boxes fit the room.

My new system is the stackable very small system designed to use a corner, pack a serious punch and only take up 2.7 square feet per stack. Right now I have dual 3/4 stacks (3-modules with dual opposed 15s in each times 2= 12-15s). Each stack is powered by a 9kw burst-capable digital SMPS amp, each plugged into a dedicated 30A home run. The signal shaping is handled by the new piece I designed and Phil built for me.

It sounds like nothing I've ever heard. Stupid clean, flat in-room to 4 Hz and limitless output in my room.

This 8xMael-X system with dual Marathons will edge out my dual 3/4 stacks below 20Hz, which I can't even imagine. OK, check that... I can definitely imagine it. It might be able to cause a tear in space/time and we'll never hear from notnyt again.

Can't wait to read all about it.

Nice score on the amps. Karaoke equipment dot com has advertised $650 per for a long time, but I don't know anyone who actually took delivery from them off hand. They still show back order.

Get some 20 or 25A fuses and keep them on hand. I've popped several in pushing the Tumults to the limits with WOTW and 6Hz sine waves. The amp is the best bang for buck I've ever used. I'll be interested in your comments.

One of my guys talked to the owner several times a while back. He said he was having the amp up fitted with some new parts (sounds vague to me), which is what supposedly caused the delay in this last shipment. Could be a stall or could be a real change, or could be they never did ship and you're getting some of the last shipment that someone was sitting on? LMK what happens with them.

Bosso

How much does 8 MXs and the amps and wood cost, vs how many more THTs could be built for that

oh, below 20Hz... so most these guys doing all these THTs don't miss the sub20Hz in exchange for all that 20Hz on up with the excellent cost and efficiency?
kryptonitewhite is offline  
post #96 of 784 Old 12-31-2010, 03:01 AM - Thread Starter
AVS Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 4,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 161 Post(s)
Liked: 375
Quote:
Originally Posted by kryptonitewhite View Post
How much does 8 MXs and the amps and wood cost, vs how many more THTs could be built for that

oh, below 20Hz... so most these guys doing all these THTs don't miss the sub20Hz in exchange for all that 20Hz on up with the excellent cost and efficiency?
cost is ~6k total. I had usable output to ~17hz with the THTs. It sounded great. It definitely missed some content in movies, but the amount of ULF content is so minimal I could care less. The goal is for something that I don't have to fire right into my walls and baseboard heating. Also, while I'm at it, I'm going for even more headroom and extension. Might as well. I like building things that are ridiculous. Coming from a drag racing background, nothing is ever enough =]

Quote:
Originally Posted by bossobass View Post
Nice score on the amps. Karaoke equipment dot com has advertised $650 per for a long time, but I don't know anyone who actually took delivery from them off hand. They still show back order.

Get some 20 or 25A fuses and keep them on hand. I've popped several in pushing the Tumults to the limits with WOTW and 6Hz sine waves. The amp is the best bang for buck I've ever used. I'll be interested in your comments.

One of my guys talked to the owner several times a while back. He said he was having the amp up fitted with some new parts (sounds vague to me), which is what supposedly caused the delay in this last shipment. Could be a stall or could be a real change, or could be they never did ship and you're getting some of the last shipment that someone was sitting on? LMK what happens with them.

Bosso
This place supposedly had 50+ in stock. Crispdeals also had them listed for $642 a piece, however out of stock. It's easy to list any price you want if you can't sell the product.

Crispdeals said they were 2-3 weeks out from receiving more. We'll see what happens to the price then. J&R supposedly drop ships or has it special order from Marathon, and they quoted me 7-10 day ship time. A few other places said they were getting them in within a week or two.

I'm guessing sixstar just received a shipment recently, because these things were GONE everywhere I called. Nobody had them in stock. I literally called and checked with a dozen different dealers. I also mailed Marathon directly, but did not get a response. I'll see if there are any manufacturing dates or anything on it when I receive them.

I'll definitely keep some fuses on hand. Are they anything special or just standard 20a bus fuses? It looks like they're nice and easy to replace, which was another plus to this amp.

The enclosures will be in a corner, so I'm hoping to get a little room gain out of it at least. I'll be finishing the sketchup model soon, as they're currently missing any form of bracing, and then creating cut sheets for everything.

You'll definitely know how everything comes out, I'm keeping this thread updated with pictures and info on the build as it progresses. I'm currently waiting for some 12gauge wire, 12ft rca cables to use for my triggers, speaker terminals, amps, and drivers in the mail. I may go to Home Depot this weekend to pick up some sheets of 3/4" MDF if I get my cut sheets laid out in time.
notnyt is offline  
post #97 of 784 Old 12-31-2010, 08:51 AM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by kryptonitewhite View Post

How much does 8 MXs and the amps and wood cost, vs how many more THTs could be built for that

oh, below 20Hz... so most these guys doing all these THTs don't miss the sub20Hz in exchange for all that 20Hz on up with the excellent cost and efficiency?

Cost is irrelevant. It's nothing more than a compromise. That's a whole nuther discussion. I don't subscribe to the "everything has compromises" philosophy. I want 3-120 Hz (+/-3dB) with 120dB total dBSPL peak capability at the seats with no compression and inaudible non linear distortion. That's what the specification for the LFE+RB calls for, and has been in place for 18-1/2 years.


This measurement was taken with a rig that's ruler flat to 4 Hz with no calibration file. Every time I post it I get resistance from nearly everyone. One guy questions the method, one guy says it's the HVAC system, one guy says there was a freight train passing by when the measurement was taken, one guy says it's only system noise, one guy says I can't do that at higher levels, one guy says there's nothing to reproduce that low, one guy says ULF has to be 140dB because of the ELC and one guy calls me the FR Nazi who chases single digits.

If all that bah-loney is the devil's advocate, then my conclusion is that the devil's system bloze.

On the subject of efficiency, if the system delivers the goods with no compression, distortion or bandwidth limitation, then it's delivering efficiently. OTOH, it it's lopping off the first 3 octaves and adding tons of distortion, then how can it be said to be efficient?

What most like about the pro sound stuff is that it's loud. It's designed to be loud at the expense of bandwidth. When you go to a rock concert, what that means is that you aren't hearing any of the instruments as they actually sound. Every sound you hear is filtered at 30-40 Hz and loaded with harmonic distortion.

When you go to the theater to see (for example) WOTW, the lightning strikes are a complete non-event. That's because the same pro sound equipment they use at the rock concert is delivering the soundtrack in the cinema.

Once, when I returned home from a business trip, my wife had bought WOTW and it was sitting in the HT room. I popped it in and watched it at ref level.

I had no idea at the time that, while I was gone, there was a power outage from a storm and when the AV preamp was turned back on, all of the setup was reset to default '0' levels. My sub system was calibrated flat with the SW channel set at -9dB.

That meant, of course, that I was watching WOTW at reference level with the sub at +9dB hot.
BALLS.

The first heavy LFE scene in that movie is in chapter 4... the lightning strikes. It made me dive for the remote and hit 'mute'. I'd never experienced anything like it.

Point being, if I had a system that rolls off at 20Hz, I would not have panicked like I did. Ignorance is bliss. So, yeah, people who have never experienced full bandwidth LFE+RB with headroom don't miss it. How could they?

That was 5 years ago. Ever since then, when people say ULF is [insert whatever lame BS story about it being unnecessary, unintended and/or inaudible], I just roll my eyes.

A final thought on price, or bang for buck. I've been around forums since 2002. I watched the fads change from one sub to the next new thing. I now see lots of posts where some guy is validating the performance of a new bang for buck commercial sub by listing a dozen commercial subs he's bought and listened to and sold or gave away in the past 6 or more years.

"New & Improved" just means the old one sucked. And, each time you upgrade you take a hit on freight and depreciation.

So, how much did that guy save in the end? And, he still hasn't approached covering the SW channel, because "it costs too much"?

Just my 2 cents. This system stomps the other one and worth every penny.

Bosso
bossobass is offline  
post #98 of 784 Old 12-31-2010, 08:53 AM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by notnyt View Post


You'll definitely know how everything comes out, I'm keeping this thread updated with pictures and info on the build as it progresses.

Good deal, and thanks for the info to date.

Bosso
bossobass is offline  
post #99 of 784 Old 12-31-2010, 09:25 AM
Bass Enabler
 
Scott Simonian's Avatar
 
Join Date: Oct 2001
Location: Clovis, CA
Posts: 13,447
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 289 Post(s)
Liked: 719
Preach it!

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 offline  
post #100 of 784 Old 12-31-2010, 10:54 AM
AVS Special Member
 
N8DOGG's Avatar
 
Join Date: Dec 2003
Location: Canada
Posts: 5,668
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 101 Post(s)
Liked: 272
I think the best part of a big system is just looking at peoples faces when something cool happens. I had friends over last weekend from Boston and they didn't even know what to say, but the look on their faces when the lightning strikes in WOTW was worth every penny I've spend on my HT. After the movie they just had blank stares on their faces after I told them I listen to the system 10 db's high than what we had it at lol. Go big or go home

Blasting brown notes for 10 years and counting!

N8DOGG is offline  
post #101 of 784 Old 12-31-2010, 12:31 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Bosso, everyone here knows 20Hz is just about the bottom, 15Hz for sure. Anything below that is a waste. You friggen Nazi.
kryptonitewhite is offline  
post #102 of 784 Old 12-31-2010, 01:46 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
15Hz on down, unless ure super rich, is a waste. I can either leave it at what Ive got with four 18's ported, lose everything from 13Hz on down and have 13Hz-18Hz extremely exaggerated, harmonics and distortion and all, or double up on amps and drivers and half my airspace. I could have spent all the wood money on more drivers for IB.



WOTWs lightening goodness

http://www.youtube.com/watch?v=czhE1d_1b9A

lightening to fan blade goodness

http://www.youtube.com/watch?v=mVSSMGB66RM
kryptonitewhite is offline  
post #103 of 784 Old 12-31-2010, 02:58 PM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by kryptonitewhite View Post

Bosso, everyone here knows 20Hz is just about the bottom, 15Hz for sure. Anything below that is a waste. You friggen Nazi.

Yeah, I've heard that rumor.

When my butcher's out of hamburger he tells me it's bad for my health.

BTW, I think what you've got goin' on is awesome. Those Fi drivers are impressive. You're poundin' the snot outta your house and the YTs are the best.

Bosso
bossobass is offline  
post #104 of 784 Old 12-31-2010, 04:05 PM
AVS Special Member
 
exojam's Avatar
 
Join Date: Dec 2004
Location: MA
Posts: 2,549
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 26
Bosso,

Side comment here. I did pick up the Marathon from Karaoke when you first mentioned them on the boards. Paid the low price and it was here within two days. Unfortunately every time I recommend that business now a days, they are showing out of stock.

James
exojam is offline  
post #105 of 784 Old 12-31-2010, 04:32 PM - Thread Starter
AVS Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 4,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 161 Post(s)
Liked: 375
I think Marathon may have raised their prices, because everyone I showed the old pricing to was like "There's no way, we pay more than that."
notnyt is offline  
post #106 of 784 Old 12-31-2010, 06:01 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by bossobass View Post

Yeah, I've heard that rumor.

When my butcher's out of hamburger he tells me it's bad for my health.

BTW, I think what you've got goin' on is awesome. Those Fi drivers are impressive. You're poundin' the snot outta your house and the YTs are the best.

Bosso

made those just for you Happy New Year!
kryptonitewhite is offline  
post #107 of 784 Old 12-31-2010, 06:54 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,134
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 204 Post(s)
Liked: 920
"want 3-120 Hz (+/-3dB) with 120dB total dBSPL peak capability at the seats with no compression and inaudible non linear distortion. That's what the specification for the LFE+RB calls for, and has been in place for 18-1/2 years."

let me play a little devil's advocate here.

what is your souce for 3hz claim bosso? i can't find anything from dolby or thx that specifies 3-120hz as the *playback* capability at the seats at 120db. i see 3 hz mentioned a lot in the spec sheets of digital equipment and even some tones on a test disk, but that is totally different...kind of like spec'ing an amp from 3hz to 160khz or something like that. it is not the intended listening range, just a wideband spec meant to cover the listening range fully, and then much more.

i see lots of websites misquoting dolby and thx (second or third hand sources), but i can't find a primary source from either dolby or thx that specifies 3-120hz at the *seating* position, though i can find many references and illustrations suggesting 20-25hz for the lower end of a "full range" lfe subwoofer. after 18.5 years of publishing this as the spec at the seating position, surely there must be at least a couple of documents from dolby or thx that discuss the importance/choice of 3hz as the lower required boundary at the *seating* position.

as for the "what is on the disk is what you are meant to hear" argument, i don't buy it. there are very few mastering rooms that are flat to 3hz at the *seating* position. that is fiction. even the monster stag theater at skywalker ranch is only 'flat' to around 22hz.

sure, there are some that actually are, but with no "rosetta stone" to match the mastering studio audio to the actual home audio, it is all just guessing, regardless of what is encoded on the disc. example: let's say that i have a MONSTER studio with quad 2242h drivers in 25hz thx cabs powered with 10kw of power and mix the bass. then you, look at the ones and zeroes on that disc and play them back over your system with 10kw of power that is flat to 3hz. we are going to hear *dramatically* different sounds even though you are reproducing the ones and zeroes 'accurately'.







minor point:i think it is 121 (115 peak lfe + 6 from redirected bass), but that is small potatoes. ~120 full range is what is needed for full range, movie reference. like concert rock? try 130db peaks.

Listen. It's All Good.
LTD02 is online now  
post #108 of 784 Old 12-31-2010, 07:05 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,134
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 204 Post(s)
Liked: 920
"What most like about the pro sound stuff is that it's loud. It's designed to be loud at the expense of bandwidth. When you go to a rock concert, what that means is that you aren't hearing any of the instruments as they actually sound. Every sound you hear is filtered at 30-40 Hz and loaded with harmonic distortion."

agree. most low sensitivity "home speakers" have no shot at hitting the 130db+ peaks one experiences at a rock concert. there is no "natural sound" of an electric guitar or a mic'd drum set, you know that bosso. the filtering around 35hz is right on and the harmonic distortion is actually *preferred* by many in such a context...most electric guitars use some sort of heavy distortion pedals or something to get it to sound "right"...play motley crue "kickstart my heart" on an acoustic and it sounds lame as hell...but as a master bass player, i don't have to tell you this bossobass! the key is to get to sound like the (massively distorted) that it does on the recording (not the original acoutstic instrument). ;-)

kickstart my heart "acoustic"...while i can hear the technical skill, and respect it, i still think it sounds...kind of lame.
http://www.youtube.com/watch?v=OY6n1UlQUtQ

kickstart my heart "electronic (aka highly disorted)"...the technical skill skill is masked, but it is still there, by the overwhelming emotional power of the music.
http://www.youtube.com/watch?v=KQMBz6HvSoM



by the way, happy new year bosso. this is all meant to be a conversation among friends.

Listen. It's All Good.
LTD02 is online now  
post #109 of 784 Old 12-31-2010, 07:31 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,134
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 204 Post(s)
Liked: 920
notnyt, even though your drives could take more than 4kw, i bet you will find 4kw sufficient. i really like the idea of "more drives, less power" vs. " less drives, more power".

maybe it has been asked, but when you watch movies, where do you set your volume (not in the receiver, but in absolute terms)? 75db, 70db? and how "hot" do you run your subs (again, not in the receiver, but in absolute spl)?

Listen. It's All Good.
LTD02 is online now  
post #110 of 784 Old 12-31-2010, 07:46 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,134
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 204 Post(s)
Liked: 920
i was thinking 115db peak from the lfe channel
+3db for the redirected mains bass
+3db for the redirected surround bass
i ignored a little from redirected center channel bass
assuming all are full range.
that gives 121+, no?

should it be higher with a 6.1 system?


your logic is that a digital recording has a max of 120db - 0db 'headroom', anything over 120db will be clipped?

Listen. It's All Good.
LTD02 is online now  
post #111 of 784 Old 12-31-2010, 07:49 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by LTD02 View Post

i was thinking 115db peak from the lfe channel
+3db for the redirected mains bass
+3db for the redirected surround bass
i ignored a little from redirected center channel bass
assuming all are full range.
that gives 121+, no?

should it be higher with a 6.1 system?

DéjÃ* vu
kryptonitewhite is offline  
post #112 of 784 Old 12-31-2010, 07:51 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,134
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 204 Post(s)
Liked: 920
DéjÃ* vu

from where krypto? shoot me a link and a drink...hny to you...

Listen. It's All Good.
LTD02 is online now  
post #113 of 784 Old 12-31-2010, 08:05 PM - Thread Starter
AVS Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 4,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 161 Post(s)
Liked: 375
Quote:
Originally Posted by LTD02 View Post

notnyt, even though your drives could take more than 4kw, i bet you will find 4kw sufficient. i really like the idea of "more drives, less power" vs. " less drives, more power".

maybe it has been asked, but when you watch movies, where do you set your volume (not in the receiver, but in absolute terms)? 75db, 70db? and how "hot" do you run your subs (again, not in the receiver, but in absolute spl)?

I calibrate to 75, as per audyssey. Then I add 3-10db depending on media. Most of the time I watch movies 5-10 hot
notnyt is offline  
post #114 of 784 Old 12-31-2010, 08:07 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
http://www.avsforum.com/avs-vb/showt...d+121db&page=4

Quote:
Originally Posted by Ricci View Post

I still stand by my comments to Graham that he simply did not turn his AVR up enough. Penn your situation appears to have been completely different with your situation actually needing a signal booster.

All I am saying is that you should not be able to overdrive big subs and clip 2000w amps at a volume level -10 db down from calibrated REF with music or test signals unless you are running things stinking HOT. There is usually 20db left on the AVR master dial from there. There is no problem there, unless you want to run your subs 20db hot in which case you would need more signal. I guess that's what people are saying. I thought that people were saying they didn't have enough gain to calibrate flat or a little hot. It seems as if most people with this problem want the sub 10db or more hotter and that's why they need a signal boost.

Calibration is usually 75db at REF volume. Watching a movie at that level with all of the bass energy from the main channels redirected too means you could possibly hit 121db or so with the subs run flat. Knock 10 db off of that for being at -10 puts you at 111db peaks with a movie. Cd's are much less hot as they don't have the +10 LFE channel and also don't have 5-7 extra channels worth of bass getting mixed into the sub too, so that puts you down in the range of 100db peaks or maybe less. Now factor in that if you are using REW for the test signals it's levels max out at -3 so by then you are in the range of 95-98db. If your sub is supposed to do 120db easily then you'll need to turn your AVR up well louder than -10 to get there. +10 would be more like it.

kryptonitewhite is offline  
post #115 of 784 Old 12-31-2010, 08:17 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
http://www.avsforum.com/avs-vb/showt...ighlight=121db

Quote:
Originally Posted by Oklahoma Wolf View Post

Haven't seen the Xmen movie to know what it's like, but Hellboy II and Serenity aren't as demanding for me as Flight of the Phoenix. Nor is Hulk 2008. But that's just taking into account the 15Hz bottom end of my tapped horn.

Flight just has these high levels of wide bandwidth LFE during that plane crash that I haven't seen equaled for pushing my TH. It's the only one yet to give me 121dB peaks at listening position, and the barrel roll is perfect for checking the excursion on the Tang Band woofers, since that frequency is precisely where excursion in the horn is greatest.

http://www.avsforum.com/avs-vb/showthread.php?t=834460

That said, Hulk did hit 120dB at LP, so it's by no means a bad choice at all. It's actually #2 on my list of go to demo movies, behind FotP. WotW is #3.

kryptonitewhite is offline  
post #116 of 784 Old 12-31-2010, 08:37 PM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by LTD02 View Post

"want 3-120 Hz (+/-3dB) with 120dB total dBSPL peak capability at the seats with no compression and inaudible non linear distortion. That's what the specification for the LFE+RB calls for, and has been in place for 18-1/2 years."

let me play a little devil's advocate here.

what is your souce for 3hz claim bosso? i can't find anything from dolby or thx that specifies 3-120hz as the *playback* capability at the seats at 120db. i see 3 hz mentioned a lot in the spec sheets of digital equipment and even some tones on a test disk, but that is totally different...kind of like spec'ing an amp from 3hz to 160khz or something like that. it is not the intended listening range, just a wideband spec meant to cover the listening range fully, and then much more.

i see lots of websites misquoting dolby and thx (second or third hand sources), but i can't find a primary source from either dolby or thx that specifies 3-120hz at the *seating* position, though i can find many references and illustrations suggesting 20-25hz for the lower end of a "full range" lfe subwoofer. after 18.5 years of publishing this as the spec at the seating position, surely there must be at least a couple of documents from dolby or thx that discuss the importance/choice of 3hz as the lower required boundary at the *seating* position.

as for the "what is on the disk is what you are meant to hear" argument, i don't buy it. there are very few mastering rooms that are flat to 3hz at the *seating* position. that is fiction. even the monster stag theater at skywalker ranch is only 'flat' to around 22hz.

sure, there are some that actually are, but with no "rosetta stone" to match the mastering studio audio to the actual home audio, it is all just guessing, regardless of what is encoded on the disc. example: let's say that i have a MONSTER studio with quad 2242h drivers in 25hz thx cabs powered with 10kw of power and mix the bass. then you, look at the ones and zeroes on that disc and play them back over your system with 10kw of power that is flat to 3hz. we are going to hear *dramatically* different sounds even though you are reproducing the ones and zeroes 'accurately'.







minor point:i think it is 121 (115 peak lfe + 6 from redirected bass), but that is small potatoes. ~120 full range is what is needed for full range, movie reference. like concert rock? try 130db peaks.

LTD found the key to the liquor cabinet again.

Digital processor and test disc produced by Dolby Laboratories.

Let's start by looking at the specs for the Dolby Laboratories Dolby Lake processor:

http://www.dolby.com/uploadedFiles/z...ifications.pdf

Quote:


Digital-to-analog outputs:
+0/-0.1dB, 3 Hz to 20 kHz

Next, let's look at the AC-3 Test Laser Disc from 18 years ago:
http://www.laaudiofile.com/testtone.html

Quote:


Dolby Laboratories'
Demonstration and Test Laser Disc
Version 1.0

Quote:


Full level frequency response
sweeps in all 5.1 channels
simultaneously.

3 Hz to 20 kHz 0 dBFS L
3 Hz to 20 kHz 0 dBFS C
3 Hz to 20 kHz 0 dBFS R
3 Hz to 20 kHz 0 dBFS LS
3 Hz to 20 kHz 0 dBFS RS
3 Hz to 120 Hz 0 dBFS LFE

Sweep 3 Hz to 120 Hz 0 dBFS LFE

Definition:
Quote:


With Dolby Digital, all five main channels are full range (3Hz to 20,000Hz). A subwoofer could be added to each channel if desired.

Quote:


The sixth channel, the Low Frequency Effects Channel, will, at times, contain additional bass information to maximise the impact of scenes such as explosions, crashes, etc. Because this channel has only a limited frequency response (3Hz to 120Hz), it is sometimes referred to as the ".1" channel.

You may visit the Master List in the subwoofer forum and pick out a few hundred titles with content to 3 Hz.

So, where the he!! would the intended playback be if not at the friggin seats?

As far as your not buying that what is on the disc is what is intended to be on the disc goes... really, man, what year is it? You think for real that Spielberg's sound designers left headroom-sucking 4 Hz-20 Hz content on his soundtrack because they never heard of a HP filter and couldn't hear it from the mix desk?

News flash... you can't h-e-a-r 4-20 Hertz.

And, those half dozen lightning strikes... were they intended to be a visual-only experience, since there is no other content besides the 4-20 Hz? The entire scene has a soundtrack that wasn't intended?

Surely you're just yankin' my root.

So, after all your "I prefer this vs that" posts, are you ever gonna build a sub and verify those imagined preferences?

Bosso
MemX likes this.
bossobass is offline  
post #117 of 784 Old 12-31-2010, 09:13 PM
AVS Special Member
 
kryptonitewhite's Avatar
 
Join Date: Aug 2008
Posts: 4,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by bossobass View Post


You may visit the Master List in the subwoofer forum and pick out a few hundred titles with content to 3 Hz.

So, where the he!! would the intended playback be if not at the friggin seats?

As far as your not buying that what is on the disc is what is intended to be on the disc goes... really, man, what year is it? You think for real that Spielberg's sound designers left headroom-sucking 4 Hz-20 Hz content on his soundtrack because they never heard of a HP filter and couldn't hear it from the mix desk?

News flash... you can't h-e-a-r 4-20 Hertz.

And, those half dozen lightning strikes... were they intended to be a visual-only experience, since there is no other content besides the 4-20 Hz? The entire scene has a soundtrack that wasn't intended?

Surely you're just yankin' my root.

So, after all your "I prefer this vs that" posts, are you ever gonna build a sub and verify those imagined preferences?

Bosso

Im sorry but I havent laughed this hard in a bit, thanks Bosso, I needed that. (not laughing AT anyone, just at wht was said, come on, it was funny )
kryptonitewhite is offline  
post #118 of 784 Old 12-31-2010, 09:28 PM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,134
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 204 Post(s)
Liked: 920
i read all of what you posted and have studied it carefully over the past several months; 90% of it is spot on. none of it suggests 3hz at the *listening* position as a requisite in order to meet dolby or thx standards.

i'm not a dick clarck victim. bad to see him so mentally torched. why do they even put that zombie on television anymore (rhetorical).

even within the alcohol cab, i'm as sharp as a samurai sword compared to you. (wait, am i vas or ltd02). i don't really mean that...it was just fun to be vas for a sentence.

not yank'n your root. wouldn't dare go near there. bosso, i don't see any 3hz at the seating position as a requisite for either dolby or thx spec.

the distinction that i think you are missing is between electronics and playback.

show me something from dolby or thx that is flat to 3 hz at the listening position.

the only point dolby is warning about is high passing the signal at 3 hz with a single filter for whatever reason. show me a single paper, peer reviewed or not, spec'd by dolby or thx that suggests 3 hz is the minimum frequency speakers should be capable to.

Listen. It's All Good.
LTD02 is online now  
post #119 of 784 Old 12-31-2010, 09:44 PM
AVS Special Member
 
Join Date: Mar 2003
Posts: 4,509
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked: 606
Quote:
Originally Posted by LTD02 View Post

i read all of what you posted and have studied it carefully over the past several months; 90% of it is spot on. none of it suggests 3hz at the *listening* position as a requisite in order to meet dolby or thx standards.

i'm not a dick clarck victim. bad to see him so mentally torched. why do they even put that zombie on television anymore (rhetorical).

even within the alcohol cab, i'm as sharp as a samurai sword compared to you. (wait, am i vas or ltd02). i don't really mean that...it was just fun to be vas for a sentence.

not yank'n your root. wouldn't dare go near there. bosso, i don't see any 3hz at the seating position as a requisite for either dolby or thx spec.

the distinction that i think you are missing is between electronics and playback.

show me something from dolby or thx that is flat to 3 hz at the listening position.

the only point dolby is warning about is high passing the signal at 3 hz with a single filter for whatever reason. show me a single paper, peer reviewed or not, spec'd by dolby or thx that suggests 3 hz is the minimum frequency speakers should be capable to.

I'm not missing any distinction or hertz.

Speakers should be capable of reproducing the source as accurately as possible.

Show me one sound designer who admits that he or she has repeatedly left -5dBFS <20 Hz content on a soundtrack that wasn't intended.

You are grasping at straws. Flat earth society.

Bosso
bossobass is offline  
post #120 of 784 Old 12-31-2010, 10:15 PM
AVS Special Member
 
soho54's Avatar
 
Join Date: Sep 2005
Posts: 3,329
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 17
LTD02,
Sorry, I pulled my post there. I was just giving you a hard time. I saw where things in the thread were heading, and decided not to add to it. Didn't help it seems.

As you responded to it, it is only fair to return in kind.

Here is me quoting myself.
Quote:


If you turn on Bass Management of any kind, and set at least one speaker to small you could get peaks above 115dB from your subwoofer, andstill be at "reference" level. This is where it gets complicated.

If the sounds are not exactly the same this is called incoherent sound. There is a formula to figure it out but lets skip it. Lets assume these are 0dBFS peak level incoherent sounds;
LFE alone=115dBSPL
LFE+1Speaker=115.41
LFE+2Sp=115.78
LFE+3Sp=116.12
LFE+4Sp=116.44
LFE+5Sp=116.74
LFE+6Sp=117.02
LFE+7Sp=117.28

If they are exactly the same they are coherent, and are a pain to sum, but here it is.
LFE alone=115dBSPL
LFE+1Sp=117.32
LFE+2Sp=119.25
LFE+3Sp=120.78
LFE+4Sp=122.09
LFE+5Sp=123.23
LFE+6Sp=124.23
LFE+7Sp=125.13

Now before you get too worried this is unlikely to ever happen. Why would you have full signal bass on every channel at the same time? There is also one other hurdle to clear, that never seems to get talked about.

Most people seem to know that the LFE channel is boosted +10dB. This is why 0dBFS is set at 115dBSPL on the LFE channel. What is mostly unknown is that before the crossover section in the process the LFE is digitally lowered -5dBFS, and is then boosted up to +15dB in an analogue output section to the RCA. All Bass Managed sound from the mains/surrounds are added in after the -5dBFS LFE step, and they are lowered by -15dBSF before being summed in with the LFE signal. (It is supposed to be boosted ~+15dB, but it isn't always.)

What this means is that if a sound on the Front Right speaker was supposed to play back at 105dB, it will still be output at 105dB. The thing that is missed is that there is only enough digital headroom left on the LFE channel for +5dB. Anything over that will clip the DSP. This means the max signal from the LFE should be 120dBSPL. Anything else is clipped off. The mastering process should have fixed any gross offenders, so around +5dB plus an extra dB should be it. See below for the extra dB.

There is the problem of Digital to Analogue conversion where the DAC can create a signal higher in dBV than the dBFS. This is known as 0dBFS+. If this perfect storm of chance were to happen you could end up with a peak higher than 120dBSPL. This shouldn't happen with commercially produced products, but it could happen. (Sound guys are human too, and forget the lessons from the analogue world still carry over.) It would be an abnormal situation though.

For more info:
Dolby Section 3.5:http://www.dolby.com/uploadedFiles/z...Guidelines.pdf
0dBFS+:http://www.tcelectronic.com/media/Le...per_AES109.pdf

soho54 is offline  
Reply DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


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