Spectrumlab Real Time Indiana Jones and the Last Crusade

[JBL 4645]

This is a simple idea that came to me this evening. An in-room-response to help find that best possible flattest frequency response (in real time) while moving the sub around at the same time, while looking at the frequency spectrum, on the Spectrumlab display on the pc monitor.

I think this idea will also greatly reduce time in finding that location with single sub bass speaker or multiple of subs for the ultimate flattest response.

The idea suddenly came too me after, frustration :banghead: with using (REW) Room Equalizer Wizard not that there’s anything wrong with the program software its just time consuming with moving the sub then running the frequency sweep which takes minutes this can way it can be cut-in-half.:bouncy:

It would help if you had an assistant to help you move the sub around and try all possible ideas like placing it above the floor will change the frequency response. In corner doesn’t do many favours unless it provides full flat response without too many dips. For me, I’m rather tough lifted the little sub up and carried it around the room while looking at the pc screen.


Anyway I made this rather quick video, no sound as its camera with video only! The film is Indiana Jones and the Last Crusade (1989). The Behringer ECM8000 microphone is placed at the listening seated position. The video is only 38 seconds long.

Spectrumlab Indiana Jones and the Last Crusade
http://www.youtube.com/watch?v=V3coi...e=channel_page (http://www.youtube.com/watch?v=V3coiXJymvk&feature=channel_page)

[Allanvh5150]

Damn! Is that movie 20 years old already? :(

[JBL 4645]

Damn! Is that movie 20 years old already? :(

Yeah it is and the sound is no way dated it still packs a punch!
:applaud:

Also forget to mention I had the SPL db metre parked right next to the ECM8000 while looking at the display of the frequency spectrum.

I’ll try and do better video next time as the lighting in the room is rather low for the camera. What I need is some natural daylight from the window during the daytime.

[Allanvh5150]

I watched the trilogy a couple of weeks ago when I first powered up my system in it's new room. As with most movies that George or Stephen have had there finger in, they are timeless.:)

Allan.

[JBL 4645]

So are there any pictures, don’t be shy now. :D


Here is, another video its 5m 18s, minutes too long, and it’s like watching paint dry.

The pink noise source is from the dts music and calibration set-up disc, track 14 all-channels, only used one output channel to carry the 10Hz to 120Hz to the Eltax A12-R while walking around with the microphone ECM8000 sub was placed on the sofa.

Spectrumlab sub bass frequency test pink noise 10Hz to 120Hz
http://www.youtube.com/watch?v=bdBpbsyC-e4&feature=channel_page (http://www.youtube.com/watch?v=bdBpbsyC-e4&feature=channel_page)


I’m off to bed now this tinnitus or other is driving me around the flipping bend, plus I have to take the cat to the pet hospital in the early morning hours, need some cat naps now, catch you later on.

[Allanvh5150]

here is one pic but I don't want to post any more until the project is finished.:)

Allan.

[Ducatista47]

At last, a center channel done right. My TV is too small to put another 4345 under. :(

Clark

[Allanvh5150]

Thanks Clark,

Beleive it or not I made the cabinet on the fly. It is 300 litre with a sub enclosure for the 12". The centre was supposed to be a 2202 with a 2425/2370 but I couldnt squeeze it in. I had a handfull of LE5's and 2404's hanging about so I jammed them together with a couple of freshly reconed 2235's and came up with something that I would describe as superb.:)

Allan.

[JBL 4645]

Allen

Interesting set-up but does it have the same timbre from left to centre to right obviously its going to be okay from left to right they are matched with the same drivers placed at the same height level.

So the 12” in the centre of the enclosure is the centre channel along with the two mid high drivers and one high frequency element. Is the box isolated from the rest of the sub to bass drivers? Is that a sealed enclosure or ported at the rear or sides?

I know one think if that where a CRT you can forget about the colour on that TV LOL it would be far gone! Plasma/LCD doesn’t suffer from magnetic strain like CRT screens.

If I rested the SONY 27” CRT on top of the JBL 4645 the colour starts to discolour.:banghead: Now if I place the Toshiba 20” on the JBL 4646 no issues, :bouncy: strange, huh?

Someone at the avs told me that a new widescreen is coming out that is about the correct shape for scope 2.35:1 films as I find the 16:9 the wrong shape its more suited for 1.85:1 W/S widescreen.

How is that supported is the flat screen fixed in anyway to the back of the wall?

Also the wall to ceiling I noticed it slopes upwards does that present an issues?

Do you have equal bass spectrum on the left and right with few dips and peaks. How about downloading the spectrumlab and running some pink noise to see if the lows look good?

Anyway keep up the good work sure it will come together at the end. By the way like the colour pattern of the walls blending onto the sub/centre channel.
:applaud:

[JBL 4645]

At last, a center channel done right. My TV is too small to put another 4345 under. :(

Clark

Have to strongly agree with Clark on that, that’s why I’ve used matching fronts LCR for 19 years now. There is less hassle in the EQ department if the room is more or less the straight along the sidewalls.

Mine has openness on one left side and it presents issues between around 80Hz the bass is sucked into the other zone? I have found a technique to fill in the missing gap of frequency by placing another speaker connected up to the LF left channel and placed the speaker in the corner and it’s like magic, ta-da!:bouncy:

The gap needs a false wall to get around the issue, no big deal, otherwise mid-range tone is fairly equal over the LCR with good dialogue panning movement, particularly with Indiana Jones and the Last Crusade there is lots and lots and lots and lots of dialogue panning happening in that film.

It was wild to hear it at its best at the Empire Leicester Square in 70mm Dolby THX, I was looking from left to right while hearing clear reinforced centre. A little delay on the centre at the right about helps the mild soft pans to left and right.

Chapter 6, when Donavan, enters the room the door opening on left channel, should be heard clearly. Also on the centre channel the same sound of the door only it has slight dryness. It’s followed with his voice on the left channel as well as centre. What you should hear or your attention drawn to the left as it was on the BIG HUGE screen in 70mm Dolby stereo.

Subtleties like Foley effects as well as body movement is clear or at least it should be with matching LCR. When dialogue is spoken in centre when Donavan, walks towards Indy, his heals on the smooth floor is heard moving onscreen left to centre. Different parts of the frequency response might smear over Indiana Jones, when he moves his left shoulder you can hear the rustle of his coat sleeve on the right front. When Indy, removes his, hat being its heard on right, and many more effects that give the scene creditability.

[toddalin]

There is a way around this. You place your sub in the seating position and move your microphone to the different areas where you would normally place the sub. The mic tends to be lighter and easier to move around than the sub. The results are comparable.

[JBL 4645]

toddalin

By that you mean the wave propagates outwards in all-directions from the seated location around the room. I’ve moved the JBL 4645 behind the sofa at present and the feeling is almost sickening there’s less boom and more vibration travelling or passing though the back of sofa.

It’s like having, back therapy. LOL Its an idea I tried out with smaller JBL control SB-5, 19 years ago, felt good with Robin Hood, not in sexual :smsex:way, just the bow and arrow effects with an oomph! LOL :D

[Allanvh5150]

Allen

Interesting set-up but does it have the same timbre from left to centre to right obviously its going to be okay from left to right they are matched with the same drivers placed at the same height level.



Hi Ash,

So many questions......The timbre of the centre channel is different for sure but my school of thought doesnt really aggree with LCR must be the same. When playing movies the main dialogue comes from the centre channel and the left and right are only used for the musical score and effects, say, when people are talking and moving from left to right. They are very close though as they are using the same mid drivers and the 12" does have a very similar sound to the 128's in the L150's. The 12" is in its own sub enclosure as are the LE5's.
The 50" Plasma is mounted directly to the wall and the sub/centre, equipment racks and LR speakers are all inside the wall as well.
The ceiling is sloped front and back. As in a THX theatre there should be no parallel surfaces and I only have 2. The ceilings and walls have carpet on them so the room is very "dead". At night with a movie playing one cant see the walls or the ceiling so it is impossible to tell how big the room is, just like at the movies.
As for dips and peaks in the response I am not really sure. The whole system is time aligned with levels normalised for sitting in the "sweet spot". Sub bass response is colossal! Even with the 2 2235's that I have running at the moment the sub bass is very good. I have a good honest 500 Watts per driver and the power amp runs about 6db below clip. To me that is running too hard and very soon I will be adding another 2 2235's in a similar enclosure in the back wall about 1.5m from the seating position.

All in all I am extreamly happy with how the project has turned out. The drivers alone took me about 2 years to gather off Ebay. I built all the cabinetry myself appart from the L86's that I have as rears. L150's for fronts and side surrounds, L86's for rear, 4 x 2235 for sub bass, and a very custom centre. ZPE power for the subs (2 x 1000 watts), ZPE power for LR (2 x 500 watts), Perreux power for the center (2 x 200 watts) and the Yamaha home theatre amp for the surrounds with about 150 watts per channel. You probably dont know about ZPE amplifiers but they are identical to Perreaux and like the Perreaux, they were made right here in New Zealand.

Apart from the Yamaha, all equipment is older than 20 years and I kept it this way as a demonstration that vintage is better.:)

I cant wait to get it completely finished. Maybe 2 or 3 more weeks.

Allan.

[JBL 4645]

I would say I’ve got a 98% smooth response with 10Hz to 120Hz range 20Hz to 120Hz at best 10Hz to 120Hz with the pink noise.

The response is uniform over the seating slight better than before with out the huge dips in the 40Hz to 50Hz range and 70Hz to 80Hz and back up to normal with 90Hz and then dropping off.

The sub doesn’t seem suited for this room at the front it had some dreadful dips and few good low ones but what’s the point if I’m going to end up scarifying for dips?

Now I have to find another location for the smaller sub for the discrete LCRS.

The JBL 4645 is placed in the rear right corner and after placing it behind the sofa and moving the sofa /sub forwards a bit to simulate the position where the sofa should be located. Wondering around the room with microphone boom stand, or fishing for a good bite, LOL I find that the rear right was by far the best.

[Allanvh5150]

Hi Ash,

Have you thought about swapping your 2240 for a 2245?

Allan.

[JBL 4645]

Hi Ash,

So many questions......The timbre of the centre channel is different for sure but my school of thought doesnt really aggree with LCR must be the same. When playing movies the main dialogue comes from the centre channel and the left and right are only used for the musical score and effects, say, when people are talking and moving from left to right. They are very close though as they are using the same mid drivers and the 12" does have a very similar sound to the 128's in the L150's. The 12" is in its own sub enclosure as are the LE5's.
The 50" Plasma is mounted directly to the wall and the sub/centre, equipment racks and LR speakers are all inside the wall as well.
The ceiling is sloped front and back. As in a THX theatre there should be no parallel surfaces and I only have 2. The ceilings and walls have carpet on them so the room is very "dead". At night with a movie playing one cant see the walls or the ceiling so it is impossible to tell how big the room is, just like at the movies.
As for dips and peaks in the response I am not really sure. The whole system is time aligned with levels normalised for sitting in the "sweet spot". Sub bass response is colossal! Even with the 2 2235's that I have running at the moment the sub bass is very good. I have a good honest 500 Watts per driver and the power amp runs about 6db below clip. To me that is running too hard and very soon I will be adding another 2 2235's in a similar enclosure in the back wall about 1.5m from the seating position.

All in all I am extreamly happy with how the project has turned out. The drivers alone took me about 2 years to gather off Ebay. I built all the cabinetry myself appart from the L86's that I have as rears. L150's for fronts and side surrounds, L86's for rear, 4 x 2235 for sub bass, and a very custom centre. ZPE power for the subs (2 x 1000 watts), ZPE power for LR (2 x 500 watts), Perreux power for the center (2 x 200 watts) and the Yamaha home theatre amp for the surrounds with about 150 watts per channel. You probably dont know about ZPE amplifiers but they are identical to Perreaux and like the Perreaux, they were made right here in New Zealand.

Apart from the Yamaha, all equipment is older than 20 years and I kept it this way as a demonstration that vintage is better.:)

I cant wait to get it completely finished. Maybe 2 or 3 more weeks.

Allan.

Oh, evening Allen I mean morning.

I know you can suspend a ceiling to slope seen them on the internet.

You’re mixing up the surrounds they should all be the same and placed along the sidewalls and rear wall spaced out to give a defused monaural surround and they should give a directional effect with split-surrounds/stereo surrounds.

That’s one thing I don’t have is carpet the walls are bare the floor is bare and the ceiling as well. It’s a bit shrilly at times but I can take it like a man. LOL I need to get it sorted, don’t I?

Your front is a lot wider than mine, which is only 10 feet 6” width, barely enough room too swing a cat around, if you get my meaning.

One thing I’m going to do now is explore with the spectrumlab the guys at Home Theatre Shack say I can use the “RTA” on the (REW) but its not to my liking its response is bit slow and I tried patiently this afternoon with it, going though settings to find something that I can happily work with.

Ending up going back to spectrumlab as I can see the graph at the top of the waterfall colour spectrum and see the peaks in the colour spectrum that need cutting with parametric EQ Behringer FBQ2496 which I did in real time while looking at the spectrumlab. I could see the hot colours toning down.

I applied a few tiny boasts and only tiny ones where there was just about I’d say 2% gaps. It’s about 98% better than it was before where I had more dips than black holes in space, well close enough. LOL

I’m going to see if I can’t tighten this up now with the LCR and the other sub bass speaker and use the time align in real time while looking at the spectrumlab response if I see dips its most likely its out of phase but the fronts are all polarity correct. Anyway I see what I can figure out.

To tell the truth wouldn’t mind getting a few DCQ2496 if I had the money, I like the look of the RTA display on that unit now that is something I can enjoy.

Oh, as for the close to clipping, it makes my skin crawl :( because I prefer less given the range of some LFE.1 track content on some films is rather high in the range or level, (you could it have it wide and yet at lower level). Anyway forget that part, the more subs the better providing you can stick them in the room and breath at the same time because mine stuck in the corner looks a bit intimidating, its like I got someone standing behind me, and yes, it makes me feel uncomfortable, [sigh].

[Allanvh5150]

Hi Ash,

What processor are you using? I am setup to run 7.1 and unless I am using one of the Dolby simulation modes, the rears don't run. There are not that many 7.1 dvd's that I have seen.

Allan.

[JBL 4645]

Hi Ash,

What processor are you using? I am setup to run 7.1 and unless I am using one of the Dolby simulation modes, the rears don't run. There are not that many 7.1 dvd's that I have seen.

Allan.

An old Kenwood KRF-X9050D THX select its about 9 yeas old. It supports Dolby stereo pro-logic/II Dolby digital/dts 5.1. Its got a digital volume db display that runs from -82db to 0db to +13db, if that helps?

The centre back surround is done with the split-surrounds/stereo surrounds outputs and feed to Pioneer VSP-200 that also supports overhead surround or matrix rear, the centre back is done in the same way Dolby pro-logic does LCR fronts only reversed around for the centre surround, side surrounds is or in most cinemas the surrounds would be whole mass going along the sidewalls and one half along the back wall, same with the other side, that’s the key to surrounding yourself.

7.1 LOL seems like Dolby or maybe if SONY who holds the patent to SDDS8 7.1 gets there sodden act together since its there technology bluray and get true five-screen out on the consumer market.

If I had 7.1 of course I’d need bluray, I’ll switch off the fronts and monitor the surrounds to see what they sound like. Is there an extra stereo surround with 7.1?

3 for the fronts LCR
2 surrounds for normal 5.0
and the .1 discrete sub bass track
2 more surrounds = 7.1 hmm, now are they monaural or stereo surround.

It would be possible to encoded an SDDS8 soundtrack and have way to switch the extra surrounds so that front information extra can be sent to left-centre/right-centre front.

Or a new AVR that has the ability to do the extra surrounds on these re-mixes or play the original theatrically SDDS8 as it was intended to be. Take U-571 for example. if you have it listen to the audio commentary, the director raves about the soundtrack and SDDS8 that takes U-571 further.

[JBL 4645]

Hi Ash,

Have you thought about swapping your 2240 for a 2245?

Allan.


I’m not edge foam fan, how about the JBL 2242.:bouncy:

The trade offs like frequency response sensitivity VS frequency response sensitivity from one to the other. Now I’d sleep better at night knowing its edge ribbon surround, unless reform kits are easy to get for 18” subs.

JBL 2245
http://www.jblpro.com/pages/components/2245h.htm (http://www.jblpro.com/pages/components/2245h.htm)

JBL 2242
http://www.jblpro.com/components/svg.htm (http://www.jblpro.com/components/svg.htm)

[Allanvh5150]

Hi Ash,

6.1 uses 1 or 2 rears in mono and 7.1 has 2 rears in separate channels.

Allan.

[JBL 4645]

Hi Ash,

6.1 uses 1 or 2 rears in mono and 7.1 has 2 rears in separate channels.

Allan.

Afternoon Allen

Oh, so their is in fact stereo surrounds on those two extra channels okay.

I guess with 7.1 you can make the surrounds 4 channels into 7 channels, hmm simple.

Now you have 10.1 or with the extra pseudo five-screen it would turn out as 12.1 and I don’t know a damn thing about mathematics expect what I hear, my mind then works out the rest.

Oh, sometimes you’ll hear information that is equal left front and rear left and if you place a decoder between each side you’ll be able to place the phantom signal sound directly in the middle of the room.

This frees up the left/right rear and left/right fronts, it’s damn complicated I worked it out a about two years or so ago, simple.

Now you have 14.1. Not that there has been 14.1 or 14 channel mix produced it’s a custom in-home-use to take the home entertainment to the next level, or beyond the norm.

You’ll need a lot of matching surrounds for this to work amplifiers as well and DCX2496 to adjust differences like phase frequency EQ delay time, oh its all good fun.
:applaud:

[JBL 4645]

Just checked over the sub bass extension Eltax A12-R for LCRS and its about 97% :) I dare not apply anymore boasts 10 in all and about 3 cuts. The boasts are tiny and to fill in the tiny gaps in the frequency response that makes u for about 97% only about 3% is missing with tiny dips.

It’s better than placing it up front I can forget that I’d have more dips to deal with and I don’t fancy sitting down in front of the FBQ2496 for hours on end.:(

I’ll take a few videos later on showing the pink noise and a few films with LCRS and LFE.1 subs.

I know boasting is very bad, and there should be other ways around it, as it adds a little strain on the amp, or you can reduce the level providing the range is their. I’d have to take some careful listening and tread very carefully as I don’t want to damage the sub, its lasted 8 years without incident.

[JBL 4645]

Looking at the LCR fronts now with my trusty ear plugs tucked in my ears as I’m running rather high 85dbc to see what I can fix with the DCX24969 parametric EQ. I’ve made some good attempts so far on the centre channel by expanding the frequency response to display on the Spectrumlab.

I’ve placed HF in mute mode for the time being until I’m finished with LF LCR.

Anyway back to the pink noise, that centre channel isn’t going to sort itself on its own.

[JBL 4645]

I‘ve taken a different approach from several positions while using spot sine wave frequencies tones from 20Hz to 80Hz so far.

Placed the SPL db meter 22” off from the JBL 4645 placed back up front believe it or not. Tested the tones one by one and reducing the level of each one that exceeds or dips below ±2db. So far I’ve noticed a different tone a smoother one. I’ve tested one of my Dolby stereo favourites laserdisc to DVD-RW original Star Trek the motion picture 1979 and the bass is notable different it seemed to accompany the LCR while in (sw-re-mix) mode.

It was time consuming adding in each filter at the problematic tones that started to exceed +2db over the seating area, but I tackled it with patients.

I still have tones above 80Hz to deal with the highest point I need to reach is 120Hz. I’m going to need another FBQ2496, or extra filter, so what I’ve done was looped the FBQ2496 with XLR lead on its output and spare phone connected to the input now I have 40 bands, I may not require all the bands but 20 has been used on channel A so far.

I could just be satisfied with the ±2db and try this out on the Eltax A-12R not sure if I’ll move it back up front or test it where it is at the back and set the sine wave spot frequencies sub bass tones up for another few hours EQ tweaking.

I’ll run a frequency sweep later and see what it shows up on REW but so far I like personal touch its not booming with excessive large peaks its kinder natural, relaxing, or more exact sounding.

Oh, I set the SPL db at comfortable 70dbc and tested each tone within ±2db.

I’ll play something deeper in the morning and while exercising cautionwith the new parametric EQ settings. The last thing I want to hear is bottoming or seeing the Alesis RA300 clipping.