Posts #438/448/546
Hi entropy455,
Here is the sketch for what might be an experimental sub horn for your project. The slight length differences between 8ft running length, and 8ft @ an angle make little difference. Hope there are not too many mistakes in the sketch, but it was done quickly...
I'd do something like this before casting any concrete.
Regards,
Hi entropy455,
Here is the sketch for what might be an experimental sub horn for your project. The slight length differences between 8ft running length, and 8ft @ an angle make little difference. Hope there are not too many mistakes in the sketch, but it was done quickly...
I'd do something like this before casting any concrete.
Regards,
that's a full blown digital mixer with 64 inputs and 64 outputs.... maybe a bit over the top with too many bells and whistles? If you are prepared to spend that type of cash, go for a high end DSP system like Lake or BSS Soundweb
Hi entropy455,
You need to design your system to make sure you get sufficiently long delays for your sub(s), woofers and midranges...
Regards,
You need to design your system to make sure you get sufficiently long delays for your sub(s), woofers and midranges...
Regards,
While I don't expect a response from Ben that indicates that he even vaguely understands these concepts or even that he's paying attention, what about everyone else? There were a number of people voting for dual subs and saying lobing and comb filtering didn't matter. Aren't we going to discuss this? Haven't I encouraged anyone to download and play with Direct or at least look at the coverage maps I provided?
If we are going to ignore this, then here's some OT for you. I told you Musk and Tesla were going to revolutionize the industry. This is a very boutique solution for rich people but the trickle down production and innovation is going to push the industry forward.
Tesla/SolarCity's Solar Roof: Solar Shingles Reimagined | EnergySage
it time to get off the
no matter where, inside or outside, no matter where the speakers are placed at some point in the soundfield there will be nulls and combfiltering or just plain wonky things (that just can't be predicted by sims!!) so the OP can get mirred in details that may or may not matter or he can re-name the thread FIELD OF BROKEN DREAMS!
it time to get off the
no matter where, inside or outside, no matter where the speakers are placed at some point in the soundfield there will be nulls and combfiltering or just plain wonky things (that just can't be predicted by sims!!) so the OP can get mirred in details that may or may not matter or he can re-name the thread FIELD OF BROKEN DREAMS!
So your plan is to not plan anything at all. Awesome. Might as well not sim the bass horn either I guess, just build something that looks like a bass horn and hope for the best. What's the worst that could happen, it's only the price of a new car being invested.
I'm pointing out issues and suggesting solutions, what do you have to offer?
This isn't exactly the response I was expecting, suggesting that software used by industry professionals be completely ignored, but it does start the discussion.
I second you on the mono vs stereo sub thing (pretty obvious, no discussion needed imo). I'm just still confused about the sub/mains crossover issue.
I did download Direct and play with it, but it's 2am over here and I can't be bothered to host all these little picture files, copypaste links and write up my blurb....
I'll tell you this much: I focused in my sims mainly on simulating the lobing in the crossover region between mains and sub. I decided to simulate 8 DBH218 and two J1 spaced 8m and suspended 2m high, to accommodate Eric's demand for "wow factor" 😀
I found that with a 180 Hz crossover point, I could optimize the lobing to be mild and take place between 200 - 250 Hz, thus keeping the kick/upper bass range unharmed.
250 Hz is the frequency range I would pull back on system EQ for a live show anyway since there is usually a lot of mud and garbage 😀
good night!
Fantastic.
For now the main issue I think is single vs dual separated subs.
The addition of mains (and placement) is secondary at this point I think. But it's good to look at the possibilities. If you don't want to host/post pics you can just describe exactly what you are simulating and I can follow along with my own copy of Direct. We can make suggestions, follow what each other are doing, find some nice solutions and post pics of those instead of posting a million pics of every possible combination.
I think a 180 hz crossover is VERY high (almost an octave higher than I showed) but at this point it's purely academic. If we can suggest a few different mains placements and crossover points the OP can test them when he has the system running before deciding on permanent placement for the mains.
Last edited:
back the truck up a second there's nothing in my statement that says abandon all sense and planning and yes i am aware of the potential price tag on the project!!
as "just" a guy who has spent most of his lifetime doing large scale sound reinforcement i'll offer this if Entropy is going to space his mains (125 hz and up) 30 feet apart then go with a single sub if he's going to space his mains 60 feet apart then go with two subs.
the narrow band comb filter nulls that can occur between sub and main can be easily dealt with so long as his crossover has sufficiently steep filters (no overlap no interaction or if you prefer less overlap less interaction)
and no i don't ignore sound design software as an industry insider i have respect for the power that simulation software can have, but i learned most of what a sim can tell me via old school methods so i don't view them as the only cannon to do audio by.
as "just" a guy who has spent most of his lifetime doing large scale sound reinforcement i'll offer this if Entropy is going to space his mains (125 hz and up) 30 feet apart then go with a single sub if he's going to space his mains 60 feet apart then go with two subs.
the narrow band comb filter nulls that can occur between sub and main can be easily dealt with so long as his crossover has sufficiently steep filters (no overlap no interaction or if you prefer less overlap less interaction)
and no i don't ignore sound design software as an industry insider i have respect for the power that simulation software can have, but i learned most of what a sim can tell me via old school methods so i don't view them as the only cannon to do audio by.
Well that actually makes some sense, you should have started with that.
But certain higher order crossovers have some ringing and other issues associated, so again it's back to priorities and compromises.
And regardless of crossover you can't get two subs playing the same frequencies at 60 feet apart to not interfere destructively.
As things progress I'm definitely going to sim higher order crossovers among a bunch of other things, this was already on the to do list but thanks for bringing it up.
But certain higher order crossovers have some ringing and other issues associated, so again it's back to priorities and compromises.
And regardless of crossover you can't get two subs playing the same frequencies at 60 feet apart to not interfere destructively.
As things progress I'm definitely going to sim higher order crossovers among a bunch of other things, this was already on the to do list but thanks for bringing it up.
As far as this is concerned, I respect theory too, and you don't necessarily need sims to show you what's going to happen if you have a good grasp on the concepts.
The problem with this is that I've been talking about the theory for two weeks now (dual subs and lobing issues) and not getting anywhere trying to explain the impact on coverage. Even with the passive crossover spreadsheet showing severe comb filtering I got nowhere, people kept saying lobing didn't matter.
So I was honestly hoping that a colored coverage map showing the theory in action would help. I understand that you and some others may not need to see it in bright colors to understand it, but some people apparently do and it's clear to see that dual subs spaced so far apart are a big mess.
I've never needed anything like this before so I guess I'm right on time.
This program would be even better if you could enter your own speaker polars and use your own speakers. Do you know of any programs like that?
This program would be even better if you could enter your own speaker polars and use your own speakers. Do you know of any programs like that?
Thank you! This was a tip I've been fishing for. I know that quality processers are out there, but I have no idea where to start shopping for one. These type of products typically have a very limited consumer market.
The Lake appears to be an analog unit. While I'm sure it is a quality piece, I have been biased by past life experiences (both at work, and my audio hobby), to keep signals out of the analog domain as long as possible.
Being a digital in/out device, the Soundweb has caught my attention. I will have to spend some time on this one - as there's a lot of configuration options here (downloading the technical specifications now). This is going to sound crazy, but I actually still hold the qualification at work to pot & polish optic cables. You can't get a much cleaner signal coupling than light! But I digress.
My ideal electronics system - for the horns. . . .
1) a PC to hold my digital recording. Nothing fancy. I want to select my song(s) and hit play (digital out)
2) I need a quality (fully-digital I/O) multi-channel crossover - 3-way stereo, with a mono summation channel for the bass horn. If it’s computer controlled, I have the PC from above.
3) I need a quality multi-channel time-domain signal delay (fully-digital I/O). I’d like a pretty fine adjustment if possible - up to a maximum delay of 0.1 seconds (any more is excessive for my design).
4) I need either dedicated D/A converters – or purchase amplifiers with a digital frontends.
Number 2 and 3 can be one integral unit. I suppose, number 2, 3, and 4 can be one integral unit. And I can make optic cables if needed. Is there a particular Soundweb model number you’d recommend?
There are many amps with digital in.
Crown I-Tech HD amps come with BSS built in as well.
Barry.
Crown I-Tech HD amps come with BSS built in as well.
Barry.
Has crown fixed the problems with their Class-D amps? I've read some nasty blogs about the early Class-D Crowns (granted this was quite a while ago). I own multiple Macro Tech VZ amps - as far as I know, they are the last generation of Crown amps built with heavy copper-wound transformer power supplies - I really like them. . .
hey Entropy the Lake has a little more under the hood than you think (not sure what your planning as a source but if Dante networking can't do what you want i don't know what your looking for?)
and maybe i'm too old school but analog still turns my crank, if it's good stuff (nothing worse than a digital console/device crash just before party/showtime IMHO)
and maybe i'm too old school but analog still turns my crank, if it's good stuff (nothing worse than a digital console/device crash just before party/showtime IMHO)
I don't have much experience with Crowns lower line stuff. I avoid all the Chinese stuff. I assume that is the stuff people have issues with.
I have a bunch of heavy Crown stuff too, and love it all.
The mission critical I-Tech line is still made in Indiana. The only one that I have seen trouble with is the four channel 3500 HD. Just too much in a two rack space chassis I think.
One bonus of having the DSP in the amp is they can get them down about 6dB better signal to noise than any other outboard solution.
I have a pair of I-Tech 5000HD amps driving a pair of Danley SH50's and four TH Minis in my house garage. The sound quality is great. The DSP is freakin' awesome.
Barry.
I have a bunch of heavy Crown stuff too, and love it all.
The mission critical I-Tech line is still made in Indiana. The only one that I have seen trouble with is the four channel 3500 HD. Just too much in a two rack space chassis I think.
One bonus of having the DSP in the amp is they can get them down about 6dB better signal to noise than any other outboard solution.
I have a pair of I-Tech 5000HD amps driving a pair of Danley SH50's and four TH Minis in my house garage. The sound quality is great. The DSP is freakin' awesome.
Barry.
Next VERY IMPORTANT conceptual design question – (sorry guys, photobucket is down right now, otherwise I’d draft a sketch – but I think this important question can be asked with words)
I want a rectangular mouth. Is there a rule-of-thumb for the aspect ratio? i.e. 3:1 width to height, or 21:8 width to height. Specifically, are there ratios that should be avoided? Assume my horn’s mouth area is 20.9 m^2, or 225 ft^2 (go big, or go home. . . . right?) Let’s say I choose an arbitrary 10 foot tall mouth. The mouth width would then be about 22.5 feet wide – making the aspect ratio 9:4
Construction method 1: I’m assuming I’d shoot a straight line from the center of the throat, to the center of the mouth (presumably parallel with the earth) – then I’d frame my concrete forms to match the exponential area expansion – while maintaining the 9:4 ratio. (i.e. for each cross-section, the vertical walls are equal distance from the centroid, and the horizontal walls are also equal distance from the centroid – all while maintaining the 9:4 ratio throughout. I understand that I must transition to round in the throat – but I don’t want to take this off topic. So in construction method 1, the horn is a straight-shot, and rainwater will not collect in the bell of the horn. .. .
Construction method 2: I could theoretically make the bottom wall of the horn flat with the ground. For this scenario, the centroid line down the horn would not be straight, however the 9:4 aspect ratio would be maintained. Or said another way, the vertical walls would expand identical to method 1, however the overhead of the horn would rise at a greater rate (as measured from the ground datum) – while still maintaining the 9:4 aspect ratio. Would this still sound as good as method 1? It would sorta be the same horn, just with a curved center-axis line. What I like most about method 2, is that people could actually walk into the horn, without climbing up an exponential curved surface. What I don’t like, is the horn has the potential to collect wind-driven rainwater. Thus I’d probably build it with a few degrees down-angle. Question: am I loosing anything by doing method 2? There’d be no parallel walls, however I would have one flat wall, down practically the entire length of the horn. Another plus, is the horn would literally be resting on the half-space plane.
Note: a 10-foot x 22.5-foot rectangular mouth is doable (from an ACI-318 perspective – i.e. I can safely build this big of horn from cast (non-prestressed) reinforced concrete. it’s doable. . . .)
I want a rectangular mouth. Is there a rule-of-thumb for the aspect ratio? i.e. 3:1 width to height, or 21:8 width to height. Specifically, are there ratios that should be avoided? Assume my horn’s mouth area is 20.9 m^2, or 225 ft^2 (go big, or go home. . . . right?) Let’s say I choose an arbitrary 10 foot tall mouth. The mouth width would then be about 22.5 feet wide – making the aspect ratio 9:4
Construction method 1: I’m assuming I’d shoot a straight line from the center of the throat, to the center of the mouth (presumably parallel with the earth) – then I’d frame my concrete forms to match the exponential area expansion – while maintaining the 9:4 ratio. (i.e. for each cross-section, the vertical walls are equal distance from the centroid, and the horizontal walls are also equal distance from the centroid – all while maintaining the 9:4 ratio throughout. I understand that I must transition to round in the throat – but I don’t want to take this off topic. So in construction method 1, the horn is a straight-shot, and rainwater will not collect in the bell of the horn. .. .
Construction method 2: I could theoretically make the bottom wall of the horn flat with the ground. For this scenario, the centroid line down the horn would not be straight, however the 9:4 aspect ratio would be maintained. Or said another way, the vertical walls would expand identical to method 1, however the overhead of the horn would rise at a greater rate (as measured from the ground datum) – while still maintaining the 9:4 aspect ratio. Would this still sound as good as method 1? It would sorta be the same horn, just with a curved center-axis line. What I like most about method 2, is that people could actually walk into the horn, without climbing up an exponential curved surface. What I don’t like, is the horn has the potential to collect wind-driven rainwater. Thus I’d probably build it with a few degrees down-angle. Question: am I loosing anything by doing method 2? There’d be no parallel walls, however I would have one flat wall, down practically the entire length of the horn. Another plus, is the horn would literally be resting on the half-space plane.
Note: a 10-foot x 22.5-foot rectangular mouth is doable (from an ACI-318 perspective – i.e. I can safely build this big of horn from cast (non-prestressed) reinforced concrete. it’s doable. . . .)
Last edited:
I have an active analog 3-way crossover on my Wife's stereo now, and I love it - very clean - works well. My concern however for my horns, is with the time-delay processor. I specifically do not want to feed the delay device with an analog signal, to have it converted to digital - processed - then converted back to analog.
Reason: it has been my experience that unnecessary conversions between analog & digital have a negative overall impact on system fidelity. That being said - I am open to the possibility that Dante networking can overcome this issue. Please remember, that I am nothing short of an absolute novice when it comes to selecting my signal processing gear. I have a fundamental understanding, but that's it. I have no idea who makes what, and more importantly - which gear is more desirable for my application. Thus any constructive input would be GREATLY appreciated. (and please remember, you are talking to a complete novice .. . .)
Last edited: