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About musgofasa

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  1. musgofasa

    230 DCV Car Audio Build

    Thanks man we talked about it once before. Actually that's where some of the 4th order ideas came from...you and some of the other guys who've worked in your build. I have never heard yours with the Evils but hopefully that will change here soon....if I'm lucky before we actually start cutting wood! Actually I'm hoping there will be more Evils at Finals for me to listen to as well. There's a lot to this build other than reaching for SPL numbers so I'm keeping a very open mind on it.
  2. Truck is coming either this weekend or next to strip down for Sound deadening. We have the mids/highs ready to go and all the wiring. 1 pair of 6.5s and one pair of tweets in the doors, 8" in the wall and a pod on the dash/A-pillar for another pair of tweets. Deck in the factory location and an Audio Control Three.1 going in either a custom center console cover or in the factory CD player location at the bottom of the dash. Box will have a mirrored front and be trimmed in with carpeted panels in the front. May even make the port removable in case we decide to play with tuning later on. 3 LP2250s, 1 LP2150, and 4 batteries in the back. I figure I will make some custom rack with LEDs and possibly more mirror back there to show off when the doors are open. For electrical the stock alternator will be left in place and a bracket added to run the second alternator at 15.2 - 15.4 volts just for the stereo. I believe 370a. Drawing up the box now so I can get some cut sheets going. We will be going to finals in KY in 3 weeks to talk to the guys at LP and with some of our friends. Hope to see some of you guys there! After that it's all about getting this thing finished!
  3. What I've shared is all I know too lol...Talked to him at length last night and he agreed to tune it a little higher to make sure it sounded good with regular rock and Pop music. He will be using the decaf and DJSNT stuff for demos when he finds songs he likes that work well with what he has. Just wants to make sure it's got some bragging rights so I'm looking good with 30-32hz I think....have had success tuning at that frequency with quite a few builds of late. Just no walls recently to compare to. I think it should translate well. recommended "optimal" is up to 8.5 per sub which would be 25.5 for three.....when I model at that it doesn't look bad but I am not putting full power on them by any means so I'm thinking a little bigger certainly won't hurt. 28 total looks good and seems to be where the models run out of gains. Much bigger nets very little and only raises the frequency where xmax can be reached. 28 gives me a good size port to work with for the area I have where the subs/port must fit too. Seems straight forward after that. less than a half db either way if I go up to 35hz or down to 26 and 30-32 gives me an in the middle (smoother) response curve. I always want to do something more extreme or complex just because I have been doing this so long and people know me for building band pass boxes but in this case the ported box just works out better. I suppose thousands of watts on a 40ish cu ft gross enclosure with 800lbs of wood should be considered pretty extreme lol. at this point all the materials are here or on the way and the truck just got the A/C fixed last week....time to start tearing this thing apart and making sawdust! Thanks guys! Build log coming!
  4. Yeah....looks like 30-32hz is a magic number.....Would anyone feel like taking a look at it with their models and see if I might have missed anything here? My happy medium comes in at 28cu ft net with a 30hz tuning. Port is 405sq inches and 26.5" long with a port velocity of 19.4m/s at 29.19hz which should prove to move plenty of hair, towels and eyeballs I imagine......I can get another 1 or 2 db going with a slightly higher tuning but it sacrifices about as much as it gains......trying to decide if cabin gain will be more than I'm thinking and maybe tune a little higher to get the peak frequency up a little higher. What do you guys think? It looks to me like any bigger doesn't make more than a db of difference and as far down as 21cu ft only cuts off the low end extension some.......All in open air environment....loaded in a vehicle I imagine the low end will be stronger than the model which has me inclined to think maybe tuning at 32 or 33 might be an idea...don't want to go too high as I don't want it to be peaky and these 18s have a mighty low fs at 25.9......that's what I'm not sure about though. Thanks again guys
  5. Not a big difference in 26 and 30hz really....raises F3 and F10 about 4hz to 28 and 23 which will likely not even be noticeable inside the cabin. Those 4 15s are tuned at 32 and will play into the 20s easily. I imagine if he really wants to focus on hair tricks we will just work out what frequency and which door/window to hold open and make sure to keep that in mind....tuning at 30 actually gains me about 3db of total output.....32hz tuning doesn't seem like much of a gain and the F3/F10 go up significantly....at least in the 30cu ft box. If I lower the size of the box the curves actually get a lot closer together but the roll off is steeper....this seems like that point of diminishing returns coming into play.....I'll play with both numbers a bit and see if I can find a sweet spot. Thanks M5.....giving me a lot to think about but now I'm getting somewhere other than spinning my tires :-)
  6. sorry...I had something in mind when I started typing that but must have gotten off track (it happens lol).....20 is typically what I shoot to stay under...I have gone as high as 30 without really noticing any noise in quite a few builds. I hear what the guy is telling me about his "music preferences" but then he also asked me to download a bunch of Decaf and DJSNT stuff so he could hear his favorite songs with the re-bassed versions. That tells me he is more likely to be abusive than he says or I train him to be so I know I need to not let him have his cake and eat it too. I agree....I only suggest that when things do fall into those generalizations it isn't a bad thing. I also recognize that it's not a bad thing if they do fall outside of them. As far as port area it would seem that the rule of thumb almost always keeps port velocity in a range I am comfortable with (almost) This is where my concerns are being addressed for sure....whether BP or Ported. I have done thousands of sealed boxes including some extremely large ones but when I look at tuning and think of these gigantic ports I think of the "one note wonders" I've seen and how many times I've heard that result. Port velocity I definitely understand. It's easy to see on the model. But port resonance might be where my knowledge is lacking then. 3-18s in 30 cu ft gives me just under 20m/s velocity with a 397sq in port 36" long tuned to 26hz and an F3 of 23hz and F10 of 19hz.....this may be tuned too low? Cone excursion shouldn't max out until 21hz (according to the model) and I plan to run a subsonic filter to limit that issue. The model shows a "first port resonance" of 187.22hz.....to be honest I'm not even sure what that means but if it is relevant to output it should be well above the high frequency cut off so I don't believe it would matter. Can you elaborate on what I might need to look at there? And yeah....I have never built a huge ported enclosure....this will be a lot more than a monkey coffin for sure. in proportion to the smaller boxes a 36" port isn't really that long when scaled up. When i used to compete in SPL tuning at 52hz and the like we wanted the shorter port to try and eek out that last .1db but we aren't chasing that number in this install so I'm a little off on exactly how to proceed. It's easy for me to see the advantages of 4th order as 25 years ago i was one of the only people building them and i sold thousands of them....granted they were small enclosures that just worked tremendously well with the subwoofers of the day but I've had a lot of success myself with the design. Since the advent of subs with heavier cones and motors a lot of those old tricks have become obselete in a way. I know this and I want to learn the new tricks which leads me to think the 6th order and even the 8th I've built a few of might be good designs for the future of SPL but for now I agree...KISS definitely makes my life easier....if this were my own car sitting in my garage to be tinkered with whenever I wanted I would be going that route without question....testing and testing and testing....but this does need to be built and sent on it's way so I'm all about the easier build. Not to mention I can throw some beauty panels in there for a quick install and it will be so much easier to work on with a flat wall. Lifting 80+lb subs into a box and crawling inside are not appealing ideas lol.
  7. I'm inclined to go with the ported enclosure more and more.....Aaron's suggestion was ported at I think 7.5cu ft per sub originally and when I look at models the ported box gives me more low end with a flatter response curve for sure. These cones are pretty heavy and of course they are 80+lb subs so maybe driving that gigantic slug of a port is ideal. With the super clean amps running them I don't think I'll have any problems with burning them up either. Now to decide just how big to make the enclosure......Even at 50 cu ft I don't run out of excursion so what do you guys think is the best way to determine where to draw the line?
  8. Thanks Billy Jack, That "constant maintenance" would be nice to avoid but yeah I can see it coming lol. I did a lot of walls back in the 90s but back then woofers weighed 20ish lbs and we did single baffle 5/8 and 3/4" wood and either none or only a few batteries. Mostly sealed boxes and a very few bandpass and up until the late 90s no ported boxes to speak of. I worked on a van for JL Audio that was a 6th order BP for 12 15s and even that was pretty well built and done. These days it's a whole other animal with 100lb+ subs and some guys running 24 batteries and 4+ alternators etc. Amazing how much goes into these monstrous builds. Reinforcing sheet metal and welding stripper poles in to keep from tearing trucks apart...Alma definitely stepped up the game lol. Now we are getting somewhere M5 I've modeled this thing in anywhere from 18 to 50 cu ft just to see what comes of it and here are some results....maybe you could offer which one of these seems like the best compromise. 1) with the power I am putting on them they never come close to reaching xmax above 22 or 23hz in ANY size box and I plan to run a subsonic filter to avoid this being an issue. That being said, if I go a little smaller (19 cu ft) they don't reach xmax until 19hz. I am comfortable with 25hz even as this guy like old rock music and the kind of bass that takes your breath away as much as the hair tricking 25hz stuff. I will be there with him for the most part to make sure his right wrist doesn't get too happy with the low stuff anyway. At least long enough to see that he doesn't just arbitrarily blow woofers. (fingers crossed you know how it is when it's not your own build). So I have another friend with some custom 18s in a blazer....2 18s in 21 cu ft and a very large port. Port velocity below 20m/s. It sounds fantastic and at 45hz will nearly close my throat. Hair tricks aren't quite as big as others out there but it's so much fun to play with. I figure the 3rd 18 in our build will probably make up for the slight loss at the very low frequency and get us the hair tricks we want if I follow the same ideas for building the box. I know "rules of thumb" are not legitimate ways of building anything. Like I said earlier they exist for a reason. If you reverse engineer enough successful builds there are a ton of them that fall close enough to them to make it noteworthy is all. That being said, I have found no few builds where the port area is huge and far more builds where it is not nearly so large. at 22cu ft the port becomes an issue. I like the curve better if I tune lower....like 26-28hz although at 30-32hz in this size it doesn't look too bad. The problem is that to get port velocity down I need a port of 390sq inches that is 36" long.....that seems excessive to me but I don't have any real experience with ported enclosures this size in a wall....the area doesn't bother me but the 36" length does. If I go 30 cu ft I can tune to 28hz and the port is a bit bigger at 480sq inches but is still 36" long ....still seems very long to me. This is the compromise I'm referring to....I'm not sure where the best line to draw is going to be. The cabin will be roughly 30cu ft in front of the box and of course it will load differently with doors/windows open/closed and people in the seats etc. I'm not sure how that will effect the performance. I'm also wondering, if I go with straight ported, is the long port like this is a normal way to build with these high excursion, high power subs? Hell maybe that's not that long when you compare percentage of port volume to enclosure total. The 4 15s above are in 12cu ft and the port is only 14" long. Also with the airspace....my thoughts are that if I go too large I will hit a serious point of diminishing returns. 22 cu ft wouldn't even require going past the second row hump lol. I'll have 10 ft of space at the back of the truck to play with. That would actually be fun for doing some lights and mirrors etc. But I want to make sure I'm not wasting that space if it can help.
  9. And here is something more like what I hope this install will look like when finished. I like using mirrors....yes we did this one a VERY long time ago lol
  10. BillyJack: 2 of the subs came in a couple months ago. Scott decided to go with 3 since we already had the amps. He told me the other day the third one should be in that week according to SSA and I posted this a few days later expecting it had arrived. When I asked he said it still hadn't come in yet :-( M5, Jay-C76: here's the thing....you call me arrogant but obviously aren't reading your own posts. I despise arrogance and both of you condescendingly dismissed one idea without offering any constructive input. I tried to ignore it and even gave feedback on what I saw with a ported design including asking "how would this be affected loading such a large enclosure into a smaller cabin space?" (Or something close to that). I also said I didn't like how huge and long the port would need to be. The reason for that is 1)port velocity and 2) tuning low enough to flatten the response. That's what I'm seeing when I model these subs in a ported enclosure. The peak output in the model is irrelevant. Tuning will require tweaking after it's installed. I know this. I came on here to ask for ideas/opinions on using such a large space to take advantage of what I have. Like I said, "what would you do if someone gave you this build?". So far neither of you has offered anything of what you would do only that you wouldn't do a 4th BP. Tbh I would much rather do a series tuned 6th order. I've even drawn up an 8th order since I've had so much time to overthink this while waiting on the subs to come in. I don't like the group delay in either case but I know I can make better use of all that space than a standard "recommended airspace" ported enclosure. It feels like a waste to use 1/3 of my available space and have a box with a huge slug of a port crammed up against the seats to net only 3-6db over a sealed alignment. It looks like 21cu ft is a sweet spot with a 300ishsq in port tuned around 30hz but that port size has higher velocity than I like. Doubling the port looks great except it isn't practical. I've asked 4 or 5 people who I trust and who have built a lot of very high output systems for opinions but none of them were familiar with these particular woofers. 1 said to go VERY large ported which makes sense but doesn't tickle me when modeled. This may be because I don't know what to expect when loading a large ported enclosure into a small cabin (hence my asking questions). The others all said that a 4th BP would be more forgiving and easier to tweak than a higher order. I do agree with this. I love doing small 6th and 8th order boxes but at this scale, if adjustment is needed it would be a nightmare I think. If anyone thinks they have an idea to reduce the workload on a higher order bandpass I'd love to hear what you've done to make it so. I'd also welcome opinions on specs to model to compare what is known prior to cutting up hundreds and hundreds of dollars worth of wood and time. i'd like to thank everyone for offering advice here but if your only input is going to be to tell me how not to build please stay out of the thread so other people won't be discouraged and unwilling to post for fear of an argument. It should be obvious I'm putting some effort into this and if I'm going to type a book like this only to get a childish one word response like "K"....well then pottasium to you too! So you think ported is the best bet. Great! Tell me more. Not why it's better but how it's better. How to get what I want out of the build with that alignment. Something I can work with that someone with my experience might not already know. Here's couple recent builds I've done in case you want to see some work. The first is 4 Ethos 15s on a Taramps 8k...just posted a 153.9 at the Sundown show. I don't like the wires hanging but it was his request in a temporary setup . The second is 4 15s in an S10 ext cab. Roughly $1500 total install that sounds phenomenal. Very clean and articulate. I like the sealed alignment here but it's not very loud at 147 for what it is.
  11. This is why I don't do the Internet forum thing anymore....5 replies to this post telling me why not to do a thing without even one constructive thought as to what would work. Saying a ported box would be better is great. Perhaps take away the "rule of thumb" BS and make any suggestion for me to follow up on. I was hoping for a technical conversation to help me work out some details but only one person (thank you DangRebel) has offered any constructive input. I NEVER said it had to be a 4th BP. I asked for ideas to help make the best use of the available space and listed everything I am working with so you would understand I'm no idiot. I've been doing this nearly 30 years and I know rules of thumb are not the bible of box building. I also know they exist for a reason and when calculations work out to be within a rule like that it's ok to take it as reinforcement that I'm going in the right direction. How about offering some insight as to what airspace, port area and tuning style you would use if you were asked to do the build instead of telling me a single reflex BP is a "waste of wood". This is a box builder's dream. I have the best of all conditions for Hofmann's iron law here. Nearly unlimited space, enough power to get the job done and I want low extension with the best compromise for transient response I can get while maintaining high output at 30ish hz. I don't care if the sub will play one note over 55hz at all and I'm not looking to compete against a meter. i think it should be possible to deliver something pretty awesome but telling me how not to do it won't get me any closer to the goal at all.
  12. Here's something of note.....I've heard that it's a good idea to tune the ported side of a 4th BP at or close to the Fc of the sealed side....at 9 and 27 the tuning would be 42.5hz which is really close to what I want and should mean a windy output in the low frequencies....it also gives me a 6" long port which is about where I want the thickness of the loading wall to be while making the ported side 15.5 square inches per cubic foot....if I go with the bigger box it tunes at 40.5hz and that works with a 16 sq in per cu ft port at roughly 6" deep as well.....could go slightly smaller to shorten it to a less deep loading wall......I'm liking the idea so far :-)
  13. musgofasa


    I've actually had about the opposite experience....there's always some beef someone has when they lose but for the most part competing and shows are a lot of fun and a lot of sportsmanship. By the opposite I mean that I've found the arrogance and attitudes the keyboard warriors online have to be draining and taking all the fun out of the hobby. That being said, I don't like the way a lot of people treat competitions.....it's as if they sometimes forget why we do what we do....not during the shows mind you...but later when people want to ask questions or share experiences online....someone saw something they liked somewhere and suddenly it can be the end all be all of all audio. Or worse the only thing they care about are numbers.....amp specs or sub parameters....or SPL scores...they forget we got into this because we liked music...especially loud music...or maybe we liked the custom installs we saw and the talent and effort that went into them. And the whole youtube thing is just ridiculous. But when I get to the shows and start getting in trucks/cars and talking to the owners and builders of the systems we are all on the same page. Competitors at least understand what it takes to get out there often and to invest in their ride. They understand what the other people have done to get their rides to the show week in and week out. They have respect for that effort....people online not so much
  14. musgofasa

    230 DCV Car Audio Build

    Fingers crossed you get this thing done for Finals brother...We'll be there for sure. Haven't seen this thing in action since you had the Ethos in it in Spartanburg like 3 years ago! 165 bound!
  15. Actually now that I do that and add filters to the ported box I checked the needed port sizes and holy smokes! lol. Ported isn't going to be as easy as I thought if I want to go that route....needs a LOT of port area AND length to get tuning down.....if I tune it even a little higher than Fs the ported enclosure appears to lose any possible advantage....in peakiness and bandwidth....not to mention overall output.....granted that's on paper....but it's worth noting....just a thought