Dave Rat - Live Sound Subwoofer configurations Part 2

[dgr89cof]

KOOL thanks for the reply, and yeah the home bass seems way more expensive like for example i seen just the Subwoofer alone cost 500 bones not your dog lol, and i thought to myself i could just make my own just using a car speaker. But thats where the thought came from. Oh and that same speaker thats $500 it only had 100 W which seems low to me.

[dgr89cof]

Im a big fan of BASS or SUBs, my question to you DAVE is i purchad a Phillip 75 W 60Hz Subwoofer at pawn. Then took the Phillips Sub apart took speakers out then. THEN i put a much bigger speaker a car BASS speaker 400 W in the Philips box, the reason i did that is it just sounds awsome with the bass shaken the house and windows LOL. Agan my question is will that do sumthing to the receiver or somehow start a fire cuz i replace the 75W philip speaker and put a 400W car speaker in its place?

[www73171]

@dgr89cof Hmmm, well if you think of the speaker as the car and the amp as the motor, it may make things clearer. The amp power is how much can be delivered to the speaker. The speaker power is how much it can handle. So in effect you put a much bigger car on a smallish motor. Ideally you would want to increase the amp power as well. Usually higher power speakers are less efficient but a more expensive large magnet speaker may put out more low end than a cheaper speaker.

[dgr89cof]

Really awsome stuff, im a big fan of sound, for example when i was helpn a friend shop for a flat screen tv his plan was to buy a big screen tv worth around $2100 and only buy surround sound RCA receiver with spackers lol yeah crappy surround sound if you ask me. But i told him i would rather have a crappy small TV and get like a bose system or definitive surround. But thats me i love sound and have lots of speakers to prove it lol i just wish i had your brain so ill know more about them.

[proaudiohd]

So why use a delayed arc then? Center towers give the best transients but focus SPL on the center. Arrays give even SPL across the stage, but the different arrival times smear the transients. Arcs help null the farthest drivers and widen the pattern, but everyone still hears some smear. If you now delay the edges, most of the crowd hears their half of the array arrive at the same time, giving clear transients with even SPL over the widest area. The center suffers though.

[www73171]

@proaudiohd Well, the main issue with center towers or clusters is they need to occupy the same space as the performers. This creates significant issues. Sight lines, too much low end on stage and pushing the audience farther away from the artist are a few of the issues. So, for real world usage, getting subs away from the center is much more practical.

[proaudiohd]

@www73171 - Yes it's too bad really! I see so often, two side stacks. Walking the crowd you can feel all the huge dead spots. Especially right up front where the most determined fans are. I wish I could go up and reconfigure sometimes. A great pdf if you haven't seen it: "a practical guide to bass arrays" by Rog Mogale

[www73171]

@proaudiohd Solving the dead spots up front and center is easily addressed by adding a few lower volume subs to cover that area in the middle. I am getting excellent results from the left and right setup I have out on Soundgarden right now. No significant nulls in the forward field and minimal sub on stage and behind the the sub arrays while able to cover 240 degrees in arenas.

[merlijnv]

Hi Dave,

Excelent and brilliant way you've found to demonstrate timesmearing of the electronical delayed horizontal sub array. I wonder what it would sound like when you insert a hi cut filter to simulate the sub frequency band instead of full range. Maybe you did, I couldn't tell. If so ignore this post.

Regards,

Merlijn

[ddfflv]

Dave, you should continue this great job - go with some end fire arrangements, end fired arc also would be interesting. The center sub (i.e. Metallica 360' version) is great piece of engineering, tell 'em about this as well!

[HAGOSLORD]

So, in an ideal world the best setup would be a sub unit that would output from a single point- so it's 100% in phase everywhere in the room- with a cardoid pattern- so there isn't too much sub hitting stage- and also some method of flattening the pattern vertically- so that there isn't too much energy hitting the roof... A kind of sausage-oid® pattern... I'm sure it's possible!

[cookie35n]

is three any difference in the sonic quality from a powerd sub or a passive sub

[www73171]

@cookie35n On the surface, there should not be. My experience is that the ultra top end subs tend to be non powered but rather have dedicated amp/processors. The reason is that using an external amp/processor allows multiple subs to be powered from one amp unit and therefore use resources more efficiently versus cost.

[1964Ears]

Dave, its interesting that you chose 47Hz to test your 2ms delay additions on. At that frequency its going to take a lot more than 2ms seconds to start cancelling it out. The kick sample you played still has the 47Hz in it. its the 60-80 or so cycles that start to cancel out. What do you think about this?

[www73171]

@1964Ears Basically what I am showing is that small time shifts effect frequencies below what one would normally think would be effected

[www73171]

@cookie35n Theoretically the only difference is that the amp is mounted in the speaker box rather than separate.

[FLIPP0P0TAMUS]

how do you do the vertical view in mapp? i cant find it. maybe im just a noob.

[ddfflv]

@FLIPP0P0TAMUS you do 2 views - plan and section. As far as MAPP is 2D software you have to create both views separately as 2 projects.

[hotweelz87]

Hey Dave so what exactly is a cardioid sub?

[DJBlondfox]

Could you give an example of a near perfect sub system in your next video?

[www73171]

@DJBlondfox I do not believe near perfect has been solved, there are numerous setups each with assets and detriments. It is the skill of the system tech/engineer to try and select the best setup for the application. I am trying to share info so that better decisions can be made.

[DJBlondfox]

@www73171 I was at a concert last year, there were 5 arcs with 5 stacks of 8 subs in each arc. The Bass was amazing, but it did separate the crowd from the bands, like you said it would. They had an uncountable wall of speakers on either side of the band, hanging from huge struts pointed kind of down at the crowd.

We were in a stadium, I was in the nosebleed section of the stadium, I had -27dB earplugs in and it still hurt my ears.

Thanks for all the advice, and keep it up, I love your vids.

[rodsteel101]

Thanks very much for this information ,,well appreciated . BTW , if you don't mind me asking , which configuration is your favorite or most practical in your experience .

[www73171]

@rodsteel101 I have 5 or so setups that I pick from depending on the artist I am mixing, venue size, width, height, whether subs are on stage or floor, hollow or solid stage, back wall, indoors, outdoors, type of sub I am using and so on.

I will do one or more videos and try and leave you with the knowledge you need to calculate and optimize some setups as well as a few go to starting points.