Speaker Impedance, the TRUTH about OHMS and BOX RISE
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- čas přidán 17. 06. 2020
- If you measure the resistance of your speakers they are almost never the same as the rating on the side of the box. Why is that? In this video we find out why and we learn about ohms, voice coils, inductance, and impedance rise, aka box rise.
Affiliate links to products used/mentioned in this video:
Parts Express*:
Dayton Reference HO Subwoofer: parts-express.sjv.io/oe95bO
Dayton Ultimax Subwoofer: parts-express.sjv.io/e4Wejg
Amazon**:
Digital Multimeter: amzn.to/3hHFG3F
*As an affiliate marketer I earn a small commission on qualified sales.
**As an amazon associate I earn a small commission on qualified sales. - Věda a technologie
👍🏼 thumbs up one of best explanations of impedance grapth, I finally understand it!
It can get pretty complicated.
Oh I’m that type of guy!! Test test test is key!! Measure ten times, cut once! Not measure once and then end up cutting ten times!! Cool upload man, your delivery is amazing!!
I've been tinkering with the lighting. I think I finally have it figured out.
Awesome info Professor DIY👍also your gain setting video is always my go when setting up amps.
Thanks!
Good stuff man! Great upload!
I think you know this trick!
The exciting thing looks like a audio transducer. Great video!
It is!
I love all the Kenwood amps you own. I own the KAC-m3004 myself like you have on your amp rack. Also a Kenwood Excelon 4 channel and mono amp. Excellent underrated amps!! I personally prefer Kenwood products over Pioneer
Kenwood makes good stuff.
Good information for sure
Thanks.
plugged many subs into the wall
It can be done safely, I would just hate for some idiot to try it and get hurt. Thanks for watching!
@@DIYAudioGuy I plugged my butter knife into a toaster element, 240volt 50hz here. I learnt never to do that again.
Shocking
love that shirt!
Thanks.
Hello brother! Im about to switch my system up and am going sealed. My question. Will i get less/more impedance rise with a sealed vs ported enclosure. I have two amplifiers to choose from. I googled but couldn't find any useful information. Thank you. Love your content!
That is a good question. I have never looked into it.
@@DIYAudioGuy when I find out I'll be sure to let you know brother
I ordered a pair of Skar SDR-10 DVC 2 ohms thinking that they were going to run at 1 ohm at the amp. Come to find out they would have been at 0.5 ohms. Had to send them back to Skar. I ordered the right pair, SDR-10 DVC 4 ohms. Now, I believe they are at 1 ohm at the amp getting 1,200 watts from an Audiopipe APMI- 1500 amp.
That sounds about right. How was the SKAR customer service? Any troubles swapping out woofers?
@@DIYAudioGuy I actually ordered the subs through Amazon. I got impatient after the first email to Skar and returned them through Amazon instead of dealing with Skar. They pretty much told me I could have received the correct ones quicker had I dealt with them.
@@DIYAudioGuy Btw, I watched your video on setting the gains with just a Multi-meter. That is very useful information. Thanks very much.
@@davidnievesjr.9478 Good! Not everybody has a DD-1 or an oscilloscope just laying around, but anyone who's doing stuff with a car audio needs to have a multimeter.
You probably would have been fine wiring them to 0.5 ohms simply because the amp is never going to see that particular DC resistive load. It's going to see a higher AC impedance load probably over one ohm. So if you wired your new subs to one ohm the amplifier is probably going to see no lower than 2 ohms and you're not getting the 1200 watts that you think you are. The most power you're probably getting is it's 2 ohm rated power and even that is only going to be at certain frequencies. On the plus side, you're not going to be stressing the amplifier as much and you're not going to be pulling as much amperage out of your vehicle.
Because 4 ohms of impedance is NOT THE SAME as 4 ohms of resistance. The multimeter likely only measures resistance. Impedance is the measurement of resistance over a range of frequencies whereas resistance is measured at a single frequency or zero frequency.
Huge difference!
Here is a great way to measure that: czcams.com/video/6g39ScWma3U/video.html
Steve Meade has a video connecting a huge ass sub connected to 120v.
It’s called woofer vs wall socket! 😮
How much impact does the port location have on loading in a multiple subwoofer enclosure? And is the created subwoofer loading impedance imbalance something to seriously consider? Thanks for your reply. -Cheers mate
Barevids mentioned that in one of his videos. It was the video where he showed how to phase match when you have two amps hooked up to two different drivers in the same box. I'm sure it has an impact, I don't know how big that impact is and I have no idea how to measure it.
Yea I saw that video where he divided the coils to each amp, guess I must of not been paying attention very well :)
@@hippo-potamus it was a very short comment he made, about one driver being closer to the port and it might make a difference in their output. One piece of box building advice that I've heard for years is that you're not supposed to have your port aimed right at the back of your speaker. If you can look through the port and see the magnet the port is in the wrong place. The back pressure that makes the system work never develops. If that rule of thumb is true then you are on to something.
Sup man awesome channel....I have a 4 ohm dvc with a two ch. amp...if I run it 1 vc per ch. does that keep it at 4 0hms?
Yes
@@DIYAudioGuy
So does using a mono amp take that option away? Only giving you the option of reducing or multipling?What am I mising here?
@@Kevin-wy8kc If you wire the coils in parallel and connect to a mono amp you can run at 2 ohms and you should be able to send more power to the subwoofer.
Well that's the thing getting older and my Kicker 12 hurts my head now so I'm getting an 8 to replace it and my amp around 1000w @ 2ohms and the new 8 is an nvx 500w so I got it in 2 ohms to bring it up to 4 so I can get it in around at the 500w range did I do that right?
Hey man, I got a DD 612 (600 watt rms) and plan to power it with a Rockford power 1500bdcp. Because this Rockford amp is very underrate (birth sheets shows 1200 watts at 4 ohm), would it be safe, to run it at 8 ohms? To get around rms rating of speaker??
Or you can just turn the amp down using the game knob. I show you the math here. czcams.com/video/MBcGOoRJ4Ro/video.htmlsi=BthOvDsjwUtFe4LQ
What are your thoughts on the Dayton Audio DCS255 10 Inch Subwoofer?
I'm using one of their 12-in models in my home theater. They are great drivers, and they used to be a great value back before inflation kicked in.
I wired 2 dual 4ohm subs to 1ohm, I’m getting a reading of .9ohms. I’m going to run it on a sundown sfb 8k the amp isn’t stable under 1ohm. Is it ok?
That is perfectly normal. If you were to measure the individual coils before you wired them you would find that the coils don't read exactly 4 ohms. If you're worried you should reach out to sundown tech support and they can verify that you should be just fine.
@@DIYAudioGuy thank you for the reply, much appreciated.
Why the cone excursion is high if I wired half the impedance of the amplifier???
I have a kicker l7 2 ohm dvc in the trunk and a box for two subs in the backseat. Ihave 2 svc 124ohm and 1 dvc 4 ohm. How do I get the maximum out of my 3000 w 1 ohm stable amp and i don't care if you don't recommend mixing impedances bc I'm ghetto af if u can't tell. I also have a Walmart 2500 that I ain't scared to run at 1 ohm even though it's rated for 2. i can't be the only person with mixed things i feel like im wasting by not using. Where do I go for information on this besides the hood bc the block is hot!? I decided to ask u out of vega, big d, or parker etc
Wire the coils on the DVC subs in series. Then wire all of the subs in parallel, you will end up with a 1.14 ohm load.
Can you wire subs straight to a home receiver
That is a great question, join us on our next live show and we will try to give a detailed answer: bit.ly/3PYKG5P
2:35 steve meade: challenge accepted
He has an old video where he did that with those big Fi's he was using in his build. They took the power no problem.
@@DIYAudioGuy I know, he also did one recently where he hooked one of his own woofer's into 240v power ☠️
I have a skar evl 12 4ohm running on a kicker dx 1000.1 @2 ohms in a ported box
Amp is rated at 1k at 2ohm and like 1250 at 1 ohm
I’m thinking about changing my setup to a dual 10 box ported box at 1 ohm.
Would this make any noticeable differences? I want windshield flex
I also have a larger amp but tight on space
So my options are single 12, dual 10 or dual 8
I don't know how much power/cone area needed to get your windshield to flex, it will often depend on the car. But I suspect you are going to need a lot more.
@@DIYAudioGuy so my last system did the trick, kicker zx2400.1 paired with an Orian hcca 12. 2400w at 1ohm. Still have amp but the woofer and box took to much space. I’m hoping 2 10s on that same amp would do better then a solo HCCA but who knows
@@taxxzempt3576 This info is general reference, far more too it, but close enough. Takes 3db to really hear much difference, but it's really not all that much louder. When people say they need more bass, 3db more usually doesn't cut it. For 3db gain, you need double the power. That's a big jump, right?
To get twice as loud equals around 10db and that takes 10x the power.
Using your 1,000 watt's, you would need 2,000 watts just to gain 3db. You would need 10,000 watts to gain 10db and get twice as loud. So, using that as your reference, anything 2,000w or more will be noticeable, you just need to decide by how much. A decent upgrade from 1,000 watts would be 3,000 watts. Anything less wouldn't be worth the hassle. Now they also say you can add a second sub, using the same power that gets split between the two and still get 3db gain. In your case 500w going to two 12's. Going to two 10's is barely any more cone area, you might gain 1.5db, nothing noticeable or worth the effort and that extra 250 watts is meaningless, changes nothing.
If you wanted to switch to two 10's to save space, you'll need to up the wattage to 2,000 just to sound as good as your one twelve. To be at all worth it, min 3,000 watt upgrade with the two 10's.
Most aftermarket alternators top out around 420 amp, some vehicles only 360 amp. Take your maximum ALT rating you can get for your vehicle times 10 and that's approx. the full system wattage you can likely support without any real issues. So a 420 would handle say 3,000w of subs and 1,200 watts worth of main speakers or however you want to split it.
Again, this is general reference and not always what happens in some cases. A lot of other factors are involved, the gear quality, the box design, it's location in the vehicle. But for those people just seeking some boom, this info gets the job done close enough.
What makes a sub 4 or 2 ohm , is it the size of the wire going around the coil or what?
I like to think of the nominal impedance rating as a shortcut that you can use to make sure that you've matched your subwoofers to an inappropriate amplifier.
Resistance of an inductor in an AC circuit will be a function of the frequency.
So is the value of the inductance measured in mH equal to the value of the impedance measured in Ohms?
No, but there is a formula that shows the relationship between the impedance of an inductor as a function of AC frequency.
Lesson learned decades back: I zzztpoofed a woofer. Replaced it. Noticed that the wires were puny. Replaced them. Fired up Credence. Damn - the other woofer blew out!
Put my fingers on the other woofer. It's working. The original woofer was working much better because I put a foot of 14 gauge in the box, and - this is major - I had 14 gauge running from a high quality Sansui amp to the speakers.
Put at least 14 gauge wires on the feed to your woofers. Look up damping factor to understand why.
Did I miss the discussion on "box rise"?
I showed a plot from WINisd demonstrating how impedance changes as a function of frequency inside of an enclosure. This is what most people call box rise, some call it impedance rise. Both names are wrong because the impedance rises and falls, depending on the frequency.
@@DIYAudioGuy oh... Thank you for responding... I haven't done a "system" in a long time and heard the term "box rise" thinking that was box flex or something... Really enjoyed your video and have subscribed and looking forward to more uploads
@@joesch11 👍
Few years ago ? I bought a multimeter in the 80s at radio shack
Age gets like that 😂 it all condenses like geological layers, brain stops growing age 25-26, after that its all downhill, fill your vessel wisely
So if I connect a 4ohm crossover to an 8ohm subwoofer and an 8ohm subwoofer. What do I have?
It depends on how everything's wired and how the crossover is designed.
If you wire the subwoofers in parallel it will create a 4 ohm load. There's really no such thing as a 4 ohm crossover they are usually just capacitors and inductors. If you've got an inductor to reduce the high frequencies from the subs then Whatever frequency it's rated at 4 Ohms should be fairly accurate for your two subs wired up to be 4 Ohms. When you're talking about car audio I would strongly suggest ditching using passive crossovers on the subs and use an amplifier that has an active crossover in it so that you can find tune the frequency, plus they are usually a steeper filter which helps eliminate vocals coming from the sub.
I love wiring my amps to half an hour home, had made my first fire a couple months ago, only because I bottomed out my subs though #smokey
Like I said, not recommended. But some people may want to do it anyway.
@diy audio guy I have a lot of impedance rise in my build so I wired lower to combat rise a little bit
Is that Captain Spalding?
What's the matter kid Don't you like clowns?
I set my gains to whatever makes my speakers and amp not too hot 😂. Bass boost off clean bass for that specific amp.
That works.
Was that a "BASS SHAKER"
Not exactly, but it's the same concept.
i put my sub on a wall outlet, a full minute of 60hz and it didnt blow, just sat there bouncing across the floor
Turn the woofer upside down and measure. What happens?
If it makes any difference it'll be completely inconsequential.
Box. Rise. It all makes sense. 🥰😍🤩🤪😜😝🤣
You won't get an accurate reading with a subwoofer or speaker turned upside down cuz it's pushing in on the rubber surround and that causes the nerves to go for them like you seen well set it up straight like you did other ones and read it that's why that one was 1.9 on this too
Transducer
Yes.
It rises
kind of funny (not really) seeing you talking to yourself on the display. thats not where your viewers are located, just mentioning.
It is VERY hard to not look at the flip-out screen. I have gotten a lot better at, but still not perfect. If I ever upgrade the camera I am going to try one with a flip-up screen. Hopefully looking up will be a bit less obvious.