Hi Art,
Let me try to pick your brain a little more, please. 🙂
Starting w/ your original suggestions of 90°H x 40°V:
Should the secondary flare be the same in both directions (horizontal and vertical), e.g.: both at 120°(or 60°v. the centerline), or should both flares open up by the same amount from the original flare which would result in 120°/60° horizontally and 70°/35° vertically?
Regards,
Let me try to pick your brain a little more, please. 🙂
Starting w/ your original suggestions of 90°H x 40°V:
Should the secondary flare be the same in both directions (horizontal and vertical), e.g.: both at 120°(or 60°v. the centerline), or should both flares open up by the same amount from the original flare which would result in 120°/60° horizontally and 70°/35° vertically?
Regards,
Tb46,
I use Bill Waslo's Synergy calculation spreadsheet v5. You will find this really helpful for coming up with your drawings, and for others to plug into HR or Akabak for simulating the responses. I have attached a filled in version with 90x40 deg horn adjusted to a lower flare freq of 246Hz which provides a 37.5in wide x 17in high x 14.6in deep horn. I have not run the Akabak sim with the injection ports driven by the 8FE200's yet but it may be tough for them to reach 100Hz without a bass reflex assist redirected back into about 75% down the length of the main horn walls. One other note - this spreadsheet is very accurate - I have cut the panels up before on another design and they glue up perfectly. Bill Waslo did a great service for the diy community with this tool (Thanks Bwaslo!).
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Oliver,
Keele's "horn break" as used (generally) by DSL and Bill Waslo's Synergy calculation spreadsheet v5 , doubles the initial angle in both directions.
Designed like that, your "Top blind guess doodle 3" a 90x40 (45x20 off center axis) the secondary portion of the horn would be 135x60 (67.5x30 off center axis).
Art
Hi xrk971 and weltersys,
Thanks for the additional information. I have worked through the Keele paper and bwaslo's spreadsheet before, but I'm starting to forget things (wonder why?).
Looks like X has a good handle at a basic design, we'll still need to know how high this box can ultimately be.
Gotta run again. Why do things keep on breaking in the oil field? 🙂
Regards,
Thanks for the additional information. I have worked through the Keele paper and bwaslo's spreadsheet before, but I'm starting to forget things (wonder why?).
Looks like X has a good handle at a basic design, we'll still need to know how high this box can ultimately be.
Gotta run again. Why do things keep on breaking in the oil field? 🙂
Regards,
EQing the bass down -4dB and it still blows these EONs away (their input set to max +6dB)
Crossed at 100hz 48dB BW
I realized that my stadiumhorns are the exact same width dimension as the FS215's height dimension. I envision a horizontal bass array in the near future.
I appreciate all the conversation that is going on about the top, this sub is going to need all the help it can get in the SPL department
My Dayton UMM just arrived. I'm about to delve into REW and see if I can't get you guys some measurements!
With music going through it, the sub sounds magical. I was getting it up to around 30V intermittently
Crossed at 100hz 48dB BW
I realized that my stadiumhorns are the exact same width dimension as the FS215's height dimension. I envision a horizontal bass array in the near future.
I appreciate all the conversation that is going on about the top, this sub is going to need all the help it can get in the SPL department
My Dayton UMM just arrived. I'm about to delve into REW and see if I can't get you guys some measurements!
With music going through it, the sub sounds magical. I was getting it up to around 30V intermittently
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Something I always love having is a limit light for my bass heavy friends. I think I'm going to try to create something with arduino and an AC voltage sense. I want the limit light to blink once the speaker voltage reads at around 80% of max.. ~40V
Do they sell that sort of thing or will I have to go DIY with it? It could also include an automatic protection relay that could cut power to the speaker. I realize that it will only work during the parts where the sub is not filter limited, but it would help nonetheless I feel
Do they sell that sort of thing or will I have to go DIY with it? It could also include an automatic protection relay that could cut power to the speaker. I realize that it will only work during the parts where the sub is not filter limited, but it would help nonetheless I feel
They look good in the light of day. I recall my sims said if you are wired in series for 8ohms you can go to 85volts. Are you running parallel in 2ohms? If it is 85v them you won't hit it with your SLA battery powered amp even with DC boost. Perhaps a non issue and it may also mean you are running tiny displacement for clean low distortion sound.
When you get your mic running I am curious if the AkAbak sim prediction that the major pressure pulse is negative and at 24ms delay? That may be a problem as max delay with 2x4 miniDSP is 7.5ms.
http://www.diyaudio.com/forums/subwoofers/262305-faitalpro-15hp1060-vs-3015lf-tapped-horn-23.html#post4071732
I double checked my sims and indeed with 24dB BW high pass filter at 24Hz, and if wired in parallel you won't hit xmax until 85 volts.
When you get your mic running I am curious if the AkAbak sim prediction that the major pressure pulse is negative and at 24ms delay? That may be a problem as max delay with 2x4 miniDSP is 7.5ms.
http://www.diyaudio.com/forums/subwoofers/262305-faitalpro-15hp1060-vs-3015lf-tapped-horn-23.html#post4071732
I double checked my sims and indeed with 24dB BW high pass filter at 24Hz, and if wired in parallel you won't hit xmax until 85 volts.
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There are a variety of meters available, this is the first one I saw:
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2ohm @ 49V is what I have my amp calibrated at. I have a multimeter hooked directly up to one of the speaker terminals to see exactly how much voltage they are pushing (what gave me the idea about the limiter) and turned up most of the way it was hitting 40V intermittently. I don't think this JL amp has any issue with the SLA. Also it is a special SLA intended for high drain/recharge for use with electric vehicles. 120A is no problem for it 🙂
Welter that is great! A lot easier than what I was planning to do. I wonder how it would work with my speakers connected for 2ohm
1.2kW now we are cooking with fire! 🙂 the 49v max sounds about right for 2ohms.
If you ever get a chance record a video with your phone or whatever and post on YouTube. Show a piece of paper flapping at the mouth when playing bass heavy music. Fun stuff.
Oh, don't forget the earplugs.
If you ever get a chance record a video with your phone or whatever and post on YouTube. Show a piece of paper flapping at the mouth when playing bass heavy music. Fun stuff.
Oh, don't forget the earplugs.
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The 48 volt LiFePO4 battery bank on my electric motorcycle can provide 400 amp peaks.
I have a 50 amp breaker to keep me from frying the motor if I get carried away.
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One of the four scales would probably give you the power range you want, if not you could tweak it with series resistors to make it light up the way you want.
Hahaaa nice! Yeah that is a ton of power! 19kW yowza! Death!
I looked into sensing AC voltage with arduino, seems I can do it with a spare 120VAC -> 5VDC or 12VDC transformer. $40 seems like a lot for such a simple thing.
VU meter is almost stupidly simple to do with an arduino, I may just do that and have the arduino control a relay to the amp's remote ON, that way I could kill power to the amps if some idiot gets too bass happy and starts overdriving. Yes, I like the sound of this a lot!
Most people prefer the sound of an RMS limiter rather than the sound of killed power...
Art pointed me towards the LiFePO4 battery for my beach radio. With solar panels, it replaced 250lbs of lead acid batteries and lasts the day. Couldn't be happier (and so is my back lol)
The lithium batteries can provide much higher instant current draw for those big bass hits without sagging voltage. And they operate at a higher voltage (slightly) which is better for those power hungry JL amps.
The lithium batteries can provide much higher instant current draw for those big bass hits without sagging voltage. And they operate at a higher voltage (slightly) which is better for those power hungry JL amps.
The JL HD amps are regulated unlike any other amp I've seen, meaning the input voltage does not matter as long as it is in range. Could be 11.8V supply, could be 14.8 from a fully charged lithium 12V- it won't matter as long as it doesn't dip below 10 and throw the amp into low voltage protection.
I am definitely a firm believer in lithium batteries, but for this setup the SLA's work great and it's also what I have on hand (high cycle 35Ah x 4). A single 35Ah seems to be doing the trick on its own.
I usually use lithium, but I need the fast recharging capability of SLA... I would never ever hook up a lithium battery to a car's alternator... Unless it was a huge lithium pack made for that application ($$$$)
RMS limiter does sound like a good idea. Minidsp seems to sell a plugin compatible with their 2x8 that has the feature built in as part of a compressor for each output. But that is $300 I don't really need to pay
I still like the idea of a hard cut, I would have a VU meter made up of 5 LED's. LED 1-3 green, 4 yellow/orange, 5 red (clip), and a separate white led to the side (protection mode "you're cut off, fool!")
I've had drunk dj friends blow subs before and it was not a pretty picture when I found out, let's just say that!
I am definitely a firm believer in lithium batteries, but for this setup the SLA's work great and it's also what I have on hand (high cycle 35Ah x 4). A single 35Ah seems to be doing the trick on its own.
I usually use lithium, but I need the fast recharging capability of SLA... I would never ever hook up a lithium battery to a car's alternator... Unless it was a huge lithium pack made for that application ($$$$)
RMS limiter does sound like a good idea. Minidsp seems to sell a plugin compatible with their 2x8 that has the feature built in as part of a compressor for each output. But that is $300 I don't really need to pay
I still like the idea of a hard cut, I would have a VU meter made up of 5 LED's. LED 1-3 green, 4 yellow/orange, 5 red (clip), and a separate white led to the side (protection mode "you're cut off, fool!")
I've had drunk dj friends blow subs before and it was not a pretty picture when I found out, let's just say that!
Here is a video from today
https://vimeo.com/107793306
The look on my roommate's face at 0:05 is priceless. That is my payoff right there, caught on video!
Amazing amazing sounding subwoofer, it just simply floors you!
I forgot to video the paper test, I'll do that tomorrow 🙂
https://vimeo.com/107793306
The look on my roommate's face at 0:05 is priceless. That is my payoff right there, caught on video!
Amazing amazing sounding subwoofer, it just simply floors you!
I forgot to video the paper test, I'll do that tomorrow 🙂
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