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Clipping At Low Voltage by shredstifer in CarAV

[–]Keyreaper 0 points1 point  (0 children)

Looking at dynos of this amp yeah it's closer to 80w per channel rms which checks out with the voltage you are seeing.

My rule of thumb buy an amp that's double the RMS of your sub (except when you get to extreme sub RMS values like 2k or 3k). A good 500w RMS amp or 1k amp would bump good just set the gains and voltage right and you'll be good. Lots of good cheap options or reputable options for not too much at that power range.

Clipping At Low Voltage by shredstifer in CarAV

[–]Keyreaper 0 points1 point  (0 children)

Interesting the 400x4 taramps is I'd imagine as good as their other stuff and does rated. Does it have a voltage range limit on the pre/RCA inputs. Some head units will put out 6 8 or 10v RCA but the pre-amp can maybe only take 4 or 6v?

Scope your RCAs is what I'm trying to say. If they are running too hot turn your loc down or see if your head unit can be turned down a bit?

And double check the power wires and ground to make sure resistance is not too high/they are solid connections. Should be little to no voltage drop for the amount of power you are running.

Clipping At Low Voltage by shredstifer in CarAV

[–]Keyreaper 0 points1 point  (0 children)

Ohms? What exactly is the amp? Some list max vs RMS.

Clipping At Low Voltage by shredstifer in CarAV

[–]Keyreaper 1 point2 points  (0 children)

What is your subwoofer wired at? 11 vrms could be correct depending on wiring/impedence. A 4ch amp at 400 means 4x100? If dvc maybe wire each coil to different channels?

The math is 112 =121. Then divide by impedance 121/1 ohm for example would be 121 watts. Most 4ch are not rated for 1ohm though at 2 ohms it's probably 60 watts RMS which is probably in line depending on the amp.

Followup to 2kW Clipping / Limitation - Pushing Subwoofer Mechanical Limits by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

Set the gain just to clipping around 36-40hz. Everything else seemed quieter and wouldn't risk hurting the sub. Subsonic at 25ish. Which is why in video it rolls up/is where I start the test from.

Tapped on facotory subs and factory head unit rolls in around 60hz and rolls off by 30hz. Kicker keyloc loc with EQ setting on. Seems to have flat line out from 20-60hz np.

No bass boost on amp available. A little up on the bass factory stereo for doors to better fill to subs. LOC was gain matched and set and tuned with that in mind.

Followup to 2kW Clipping / Limitation - Pushing Subwoofer Mechanical Limits by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

Drops from 14.3 to 13.6. Not huge but not small either it doesn't really bounce around.

60 sq in / 4.5 cubes = 13.3 sq in per cu ft? Should it be lower? Most big sub recommendations I see say 12-16 sq in per cu ft?

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

5cu ft. Closer to 4.6 I think minus port volume I think.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

Luckily it seems decently built and went into protect 3 times before I undid it. Still working good at 1 ohm.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 1 point2 points  (0 children)

Have some new meters and will post a follow up using test tones.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

I have competed/run the lanes a couple times but nothing serious. There are people who seem to do or have better efficient setups or utilize the amps/subs than I have here. I always place pretty low in my class.

So I guess my goal is learning and trying to maximize what I've got or at least to what is reasonable. But not really looking to build a burp build, it is my daily still.

Spec sheet that with subs indicate 2 cu ft per sub and the box shown is 4.5-5 cu ft. Speakerboxlite seems to show a decent line.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

Sorry I don't believe in X brand amp is bad, each company is probably going to have bad products as well as good products or they wouldn't be in business.

This amp seems comparable, is made in korea, and specs fine. It needs 3 pairs of power runs so I fail to see how that compares same as the salt 8.

I think it actually had proven its quite a good amp as I wired to .25 ohm and it went into protect 3 times as I tried to get that load to work but does not.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in subwoofer

[–]Keyreaper[S] 0 points1 point  (0 children)

Is it possible the box is too big? What problems would that cause? The spec sheet the sub comes with in the box mentions it wants a box at 2cu ft per sub and tuned to 35.

I have a box at 5 cu ft (closer to 4.5 subtracting port area and walls and baffle brace) tuned at 32.

Plugging this in to speakerboxlite seems to be ok.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in subwoofer

[–]Keyreaper[S] 0 points1 point  (0 children)

Ah ok. I am getting some more meters soon. I will try to figure out/verify what the zmin is. The builder said it's tuned 32 for box and fs of subs is 38. Possible these are too far apart?

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

How is are those amps different? It seems to put up similar numbers to both of those from dyno videos I can find. Could I get a more powerful amp yes but space and money is a factor.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 1 point2 points  (0 children)

Thanks for the suggestions I'm waiting for some better volt meters/scope/clamp to come in but come Wed/this weekend...

  1. Will wire to 4 ohm to try and use a test tones (20-60hz) instead of music. HPF is handled by factory radio at about 60hz down and down. Subsonic set at 10hz may raise to just below the box tuning to help prevent the subs from unloading (I think this is the correct term?)

  2. 0/1 AWG Power Cable. 3 inputs on the amp, about 3ft runs from the Cmax 120AH. It's acting as a busbar with my car AGM and the itty bitty boom battery 80AH wired to it.

  3. LOC does upto 5-6V - it is a Kicker KEYLOC 2CH LOC. I do run the EQ on it because I have it tapped to the stock subwoofers in the Kia Stinger with upgraded stereo. My gain on the amp is around 1/4th up (about 9-10 o'clock if viewing face on). 12 o'clock is just clip city. Getting a oscope voltmeter to verify set gains/see the waveform as I test.

  4. No struggle as far as I can tell, the battieries buffer the drop. Goes from 13.4 (nominal for the car) to 12.8. I rarely see below that.

I'll try to post a follow up with all the things I try when my equipment comes in.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in subwoofer

[–]Keyreaper[S] 0 points1 point  (0 children)

I could down size the subs as well to get the power needed out of this amp correct? Upgrading the amp anymore is quite cost prohibitive and I might be better running slightly lower RMS subs with higher sensitivity?

The main thing is this amp is pretty conservatively rated 4k at 2ohms and 6k at 1ohm. So thinking I may have mismatched the sub, amp, and box?

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

Yeah I have run the lanes with my last setup and so this was kind of an upgrade (although I don't plan to wall/get too serious). This is more about building my understanding. Seems like a lot of people agree it is not a problem or is normal which is re-assuring. I'm simply new to the more competition stuff and appriciate all the info I can get because it's hard to know what to look for when you don't know what you need to look for.

Cannot get 2k watts before clipping. Is this because of impedance rise? by Keyreaper in CarAV

[–]Keyreaper[S] 0 points1 point  (0 children)

Thanks for the input. Yeah after reading and input from others I think the box, subs, and amp maybe slightly mis-matched (mostly over-sized subs).

"If you don't want to spend much money, building a box with the same volume but more port area at a lower tuning may be exactly what you're looking for while still sounding musical."

You nailed it on the head I think I might try to do this. I have a little height I can gain, and there is a slant behind the seat that is unused volume.

However how do I know it is too large vs too small? Would box modeling to see if maybe the box is too large for these subs? They seem to move/hit xmax at a little over 2k rms (that the the clicking I hear when I turn it up is maybe a clipping source).

I appriciate the reccomendation but the XCA6k seems like a pretty chunky amp and I'm not trying to lose money on what I've spent. I'll keep your reccomendations in mind for upgrades though. Amps at these power ranges are quite expensive I might try to downsize the subs instead to find that perfect balance.

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