Finally finished up my project. Special thanks to everyone that helped me out.
Figured I'd post some pics. It's a Peavey Low Rider 18" paired with a bridged Behringer EP2000. It's a 5.5 cube box tuned to around 32hz.. It's purely for music and parties.
I did all this on my porch and party room, definitely not a master wood worker or have done audio work like this before. Yes I know things could/should have been done differently but turned out quite nice. Hits decent, though I think it overall needs some adjusting.. (will touch on that at the end)
4 cans of truck bedliner. Still have to put on the grill guard.
As I was mentioning earlier I think it needs some adjusting.. it hits hard, but not nearly as it should. Some songs it barely hits at all... (when my old sub would be going hard) It just sounds empty on a lot of bass heavy songs. I currently have the amp set up as follows.
Clip limiter on
Low cut filter 30hz (as opposed to 50hz)
Low cut filter on
Bridge mode on
The signal is coming from a home theater receiver "subwoofer out" through a thick subwoofer rca cable into a 1/4 mono TRS adapter, into the amp. The amp is hooked up to the driver using very thick copper stranded speaker wire.
Not sure where the issue is.. (maybe amp settings wrong / perhaps I need to use a speakon connector / maybe the box is at fault / maybe it's tuned all off)
Figured I'd post some pics. It's a Peavey Low Rider 18" paired with a bridged Behringer EP2000. It's a 5.5 cube box tuned to around 32hz.. It's purely for music and parties.
I did all this on my porch and party room, definitely not a master wood worker or have done audio work like this before. Yes I know things could/should have been done differently but turned out quite nice. Hits decent, though I think it overall needs some adjusting.. (will touch on that at the end)
4 cans of truck bedliner. Still have to put on the grill guard.
As I was mentioning earlier I think it needs some adjusting.. it hits hard, but not nearly as it should. Some songs it barely hits at all... (when my old sub would be going hard) It just sounds empty on a lot of bass heavy songs. I currently have the amp set up as follows.
Clip limiter on
Low cut filter 30hz (as opposed to 50hz)
Low cut filter on
Bridge mode on
The signal is coming from a home theater receiver "subwoofer out" through a thick subwoofer rca cable into a 1/4 mono TRS adapter, into the amp. The amp is hooked up to the driver using very thick copper stranded speaker wire.
Not sure where the issue is.. (maybe amp settings wrong / perhaps I need to use a speakon connector / maybe the box is at fault / maybe it's tuned all off)
Bob 3,
Testing the box tuning would be the way to see what is happening.
Put a silver or white dot on the cone, sweep a sine wave (or down load sine waves if you dont have a tone generator) around your predicted tuning, the cone will have minimum excursion at Fb.
32 Hz Fb is pretty low for a Peavey Low Rider in that small of a box (it will have a very rolled off LF response), to get some kick out of it you should raise the tuning to around 38 Hz, if your box actually comes in at 32 Hz Fb, saw off a bit of the port shelf and test.
Art
Thanks Art! I shall put on that white dot and do the sweep.
Should the low cut (high pass) filter be set to on? 30hz or 50hz? Maybe that has something to do with it also.
32hz must be way too low.. I agree. I'm just looking for that chest pounding bass. Sound quality is nice, yet not as critical. I have no problem sawing that shelf. Further, I have a ton of polyfil, I could stuff the crap out of it..? Likely gain an extra cube.
Ps why 38hz? Balance between quality and output?
Leave the low cut (high pass) filter "off" while determining Fb.
Polyfill will reduce output.
"Chest pounding bass" is generally 60-120 Hz, 32 Hz is more "pants leg flapping", a 38 Hz tuning in your box should give you a bit of both, but the low tuning you (may) have sacrifices both.
Will leave filter off. Should I leave off indefinitely? If not, 30hz or 50hz?
Polyfill will reduce output? Assuming I cut the port down, polyfill lined should make the enclosure a bit larger, helping overall? If still tuned to 38hz. Or not worth it.
Here's my other thread if you have some time to reference. They're claiming some other things. Bobbo's sub build (pics)
Will do the fb test right now.
Thanks again so much.
Personally not a huge fan of the wide slot port, it's not the same as a round port which is optimal. Look into that. Another reason I like round pipe ports is that they are easy to shorten/lengthen. To bring the tune up you're going to have to cut a section of that port from the inside. Also, if you have two 4" round ports, you can plug one or both to get better extension for movies, normal music listening, etc.
That's 3/4" mdf? It's not real stiff in a large panel like that, should have used plywood (cheap 5 ply birch is MUCH stiffer, also lighter). The MDF is absorbing energy.
The rod bracing is not effective. You need to get this properly braced. Get some 1/2" cheap birch ply, cut 1.5" slats to length and glue them lengthwise on the 1/2" side inside the box every 4 to 6" inch. Think of a 2x4 stud wall. This will massively stiffen it and result in more output. Also do similar bracing on the baffle behind the woofer. This can all be done by only removing the woofer. It will help, alot, especially with punch in the 50-100 hz range. Adding this wood will also slightly decrease internal volume, which will increase the tune slightly. Try this first, then shorten the port. Do NOT stuff it.
Another thing to consider is that your old sub was probably a common commercial design that had a peak somewhere in the 60-120 hz region. This will give you that bass presence in most pop music. It's also the reason for kick bins on some PA's. You've got a design that has a real nice gradual rolloff that should combine well with room gain and give a nice flatish response, but it's not a gut busting party sub. Based the plots you linked to and your goals, I would re-tune to at least 40 hz, if not 45hz. Or rework it to a couple 4" round ports that you can use to play with the tune.
Oh and yes, adjust the subwoofer gains on your receiver, just like you mentioned in your other thread.
Otherwise looks real nice and pro!!
That's 3/4" mdf? It's not real stiff in a large panel like that, should have used plywood (cheap 5 ply birch is MUCH stiffer, also lighter). The MDF is absorbing energy.
The rod bracing is not effective. You need to get this properly braced. Get some 1/2" cheap birch ply, cut 1.5" slats to length and glue them lengthwise on the 1/2" side inside the box every 4 to 6" inch. Think of a 2x4 stud wall. This will massively stiffen it and result in more output. Also do similar bracing on the baffle behind the woofer. This can all be done by only removing the woofer. It will help, alot, especially with punch in the 50-100 hz range. Adding this wood will also slightly decrease internal volume, which will increase the tune slightly. Try this first, then shorten the port. Do NOT stuff it.
Another thing to consider is that your old sub was probably a common commercial design that had a peak somewhere in the 60-120 hz region. This will give you that bass presence in most pop music. It's also the reason for kick bins on some PA's. You've got a design that has a real nice gradual rolloff that should combine well with room gain and give a nice flatish response, but it's not a gut busting party sub. Based the plots you linked to and your goals, I would re-tune to at least 40 hz, if not 45hz. Or rework it to a couple 4" round ports that you can use to play with the tune.
Oh and yes, adjust the subwoofer gains on your receiver, just like you mentioned in your other thread.
Otherwise looks real nice and pro!!
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Yeah I hear ya, unfortunately it's too late now. The slot port was much easier for me to do at the time. My next project (that sick 4 12"s you made) I'll do pipe ports.
Yes that's 3/4 mdf. It was the common consensus for what to use. I shall pick up some birch play and reinforce the walls. Pretty simple to do.
Exactly! It definitely hits. Don't get me wrong. Yet I just felt for what this is, it should really be chest pounding and deep. It sometimes sounds kinda flat and empty. Almost boomy.
I was afraid to tune it any higher because I wanted it deep and not boomy and many said I'll only gain a few dbs. Yet it seems that the greater the tune the more "gut busting" as you'd say. As yes this is a party sub. Maybe I just have my facts off.
I'll add bracing and look to reducing that port. I can fit a jigsaw in there. I have two 3" precision ports I can add on top of the slot port, if that works. (though I may have that backwards and need less portage..)
The box is very well sealed up. I have 5 standard jbl speakers to utilize, they use just standard speaker wire. I assumed I'd need a home audio receiver.
Most of your questions have been answered, but use the 30 Hz filter, the 50 Hz will cut too much.
Polyfill definitely will reduce output in the sub range (30-120 Hz), and LTD02 is correct, in your undersized box, the difference between your actual tuning of 33.5 and 38 does not amount to much.
Attached LTD02's sims and Peavey's actual cabinet response curves for comparison.
If you want to get low bass in a 5 cube cab, a pair of speakers like the Lab 12 or TC Epic 12 will kill the Low rider. But you already have built a too small cabinet for your 18", so solly
.Turbodawg's bracing suggestions are valid, surprisingly bracing affects the upper "kick" sub range (around 80-160 Hz) more than the bottom octaves.
If you jam a divider (or two) in the port (use some paintable black caulk for sealant) it will help bracing and also make the port a bit more effective.
As somebody else mentioned, multiple ports also allow for "step down" (Electro-Voice term) operation by plugging a port the tuning goes down.
Attachments
Most of your questions have been answered, but use the 30 Hz filter, the 50 Hz will cut too much.
Polyfill definitely will reduce output in the sub range (30-120 Hz), and LTD02 is correct, in your undersized box, the difference between your actual tuning of 33.5 and 38 does not amount to much.
Attached LTD02's sims and Peavey's actual cabinet response curves for comparison.
If you want to get low bass in a 5 cube cab, a pair of speakers like the Lab 12 or TC Epic 12 will kill the Low rider. But you already have built a too small cabinet for your 18", so solly
Turbodawg's bracing suggestions are valid, surprisingly bracing affects the upper "kick" sub range (around 80-160 Hz) more than the bottom octaves.
If you jam a divider (or two) in the port (use some paintable black caulk for sealant) it will help bracing and also make the port a bit more effective.
As somebody else mentioned, multiple ports also allow for "step down" (Electro-Voice term) operation by plugging a port the tuning goes down.
Yeah I decided the box frequency is fine at 34hz. I'm still going to reinforce the bracing yes.
and whelp damn at this sub/box combo... I definitely don't want to be stuck with an average system. Like I said it hits decent with some songs, then others a bit flat at times. Yet overall not as I expected. Nothing chest pounding. If it doesn't work out I'll look to replace with a different 18" or retrofit smaller size sub(s)...
One thing.. I am using a 25ft unbalanced signal from my crappy home theater receiver. I've been told to level match the signal so I was going to pick up a DI box to boost and match. Which should help tremendously. Should I still do so? Or is this sub/box the real culprit..
It kind of sounds like an elephant farting through a kazoo...
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Usually the biggest culprit is the room, which can make mincemeat of the best sub.
Your amp can probably be driven FTB (see if you can hit the clip lights) by your crappy home theater receiver, but receivers usually have a very high "sub" output ranging upwards of 250 Hz at only 12 dB per octave, so amplifying that just makes for loads of mud on a sub like yours that has plenty of (crappy sounding) upper response, usually including a port resonance around that range.
If you are serious about having a "better than average" sub sound using a power amp, you need to get into DSP, whether using the Mini DSP, a DBX DriverackPA, the Berhringer, or whatever.
Unaware of what FTB means.. yes I can hit the clip lights. Anyway I'm getting such conflicting responses..
I don't want to get into DSP, etc. I meant better than average as in better than my basic BIC VK12 that was plugged into the same crappy home receiver in the same room. That little 250rms 12" shook the house. I thought this was going to dominate that. It just sounds a bit flattish and lacking and I'm left confused. If it's the signal going in, I'll get a proper DI box. If it's the subwoofer/box itself I'll swap out the sub.
I thought this was good advice on getting your gains set properly:
First build: Dayton 15" HO and iNuke3000DSP
What are you running for the low pass crossover on this.....?
First build: Dayton 15" HO and iNuke3000DSP
What are you running for the low pass crossover on this.....?
Will look into that thread.
I'm not running a separate low pass crossover.. Just whatever the "subwoofer" out on the ht receiver provides, and/or anything on the EP2000 amp.
Also I was going to pick up this
Amazon.com: Rolls MB15 Promatch Converter: Musical Instruments
as I've read countless articles on how consumer to pro audio is just never a good thing. Can't hurt.
I would be concerned about this. You may be sending signal (far) above 100hz to your sub, which could be causing weird phase/time cancellations between it and your mains in the midbass. Bass "hit" is partly transient response - think of a square wave. A square wave is composed of many sine waves of various frequencies overlapping. Due to crossovers, when you send your system a kick drum, the mains and sub will both see some of it. If there is a timing difference between them, the response will not be natural. Even worse if the are both trying to send signal at 150 hz and don't match up due to location differences, resulting in cancellation. Optimally, at your crossover frequency the drivers have to be time aligned - the easiest way to do this is to have them located the same distance from the listener.
If you're HPF is set at 30Hz and you're tuned to ~33 Hz, the output at 33Hz is already being rolled off by the filter so the port s not doing anywhere near as much as it should. That is costing you a lot of output potential since you're not letting the port work for you. The driver is basically trying to work in a sealed box if it does not get to excite the port's fundamental resonance. Did you test T/S parameters and model this design prior to building it?
Gotcha. Will look into that and correct the signal. I've run it without the mains completely, I still get the same general response.
It's already being rolled off at 33? Maybe I should test with the low cut (hp) filter off... I'll be home in an hour. Some have mentioned it can be run without..
The signal is coming from the home receiver sub out, not sure if that is already sending certain filtered frequencies..
I modeled this before I built it, someone else helped me. The box came in at the smaller side for this sub, yet it would still be ok. He recommended 30hz or 35hz, with the hpf set at 30hz, I went for the middle.
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