tuning amp for kicker ks

I'm using speaker level inputs on a 50 watt RMS amp which is forcing me to keep the gains at zero (but maybe allows me to run the amp more efficiently?). I'm testing the hi-pass settings using Massive Attack's "Angel", Morphine's "Rope in Fire", and Mad Season's "Wake up."

I'm finding I have to set the hi-pass at around 150hz (200hz would probably be even better if I want to play these types of tracks at full volume or even nudge the gain up a bit) to prevent distortion on a par of 6 3/4" KS components (supposedly rated for a 60HZ hi-pass and 120 watts). Is that normal?

When I add a sub if I'm doing a low pass filter at 125-200hz will that screw up my sound stage or compromise the sub?

Just trying to tune the components as good as I can before I put a sub in.

 

I’m interested to see what the more knowledgeable pros have to say but none of this sounds right to me. Is your amp 50 watts total or per channel? Are you running passive or active? When you say forcing you to keep your gains at 0 do you me you get distortion if you try to turn them up at all? If your speakers are rated for 60hz then that’s what you should tune them for. I’m not sure exactly what you have going on but something is definitely not correct. Also I think you should read up on how the high and low pass filters actually work. Your sub should be about 80hz and below and your components should pick it up from there.

 

https://www.diymobileaudio.com/threads/low-frequencys-on-mid-woofers.248738/page-2

Yes 50Watts RMS x 4. Doing a bridged 3&4 for the sub.

I think the issue is the speaker level inputs are not being lowered in the amp, just being amplified up from the stock HU levels. A LOC would be an option but the reviews are mixed and it just adds yet another power draw (and ground connection, etc. etc). Also, the sound I'm getting is promising for the price point except for exceptionally bassy tracks.

I've found some subs that have frequency response of 30-500HZ and can run at 150 watts 4 ohm (under powered for a sub I know but that's what I'm working with) but the issue with subs apparently is moving the sound stage too far rear but maybe that's not a problem practically speaking at around 200 HZ which apparently is where the KS wants to be.

Oh yes...the joys of car audio on a budget. Wait until you see the sub I'm look at (it costs $50).

With all that said aside from a getting a few bassy tracks to play well I'm basically happy with where I'm at with the KS and the ancient Alpine MVP-f300 amp I've got but I think I'd get at least a 75 RMS per channel if I were ever drop the dough on a new amp.

 

Stock radio? What year? What is the amp model? Need this info.

 

2015 entune non-jbl, no navigation has sirus, backup camera, amp is a discontinued alpine MVP-F300 (https://www.crutchfield.com/p_500MRPF300/Alpine-MRP-F300.html) using speaker level inputs

 

FWIW, I have my crossover set at 200Hz, 24dB/oct. I found this reduces the nasty resonance I get from the front doors, which seems to be when the E3-note hits (~165Hz).

The 200Hz isn't a problem for the sub if the woofer/box combo has a good flat response. Otherwise, if the box is too small for the woofer, the output rises with frequency.

Lowering the bass on the head unit and raising the gain on the sub amp also helped me.

 

Good to know, thanks a bunch for the confirmation. I noticed a lot of resonance below 200hz also especially in the window control plastic piece. I've heard felt tape is the cure for that. I'll likely add some more deadening to the door plastic since I have to get into the door to reduce the crossover high frequency boost down to 0db - that and I found a door clip on the passenger floor after the speaker install.

Now to pick out a sub. Was considering the MX TN10-04 10" for $55, it only goes up to 160HZ tho. I think that's what I had in my last set up (handed down) and it sounded pretty good. JL Audio 8W1c3-4 is an expensive contender also.

 

So I don’t have specifics on that stereo, I can just say that the Toyota radios will begin to distort well before full volume. On mine, that’s at volume setting 49.

I wanted to look at the amplifier manual to see what the input sensitivity voltage range for high level inputs is, but since Alpine sucks, that specification is not listed, only the low level input is. There is a limit, it’s nice to know what that is when choosing equipment.

My thinking is that you are over driving the signal into the amplifier, that you’re expecting a lot more than 50W can give you, and consequently you get a lot of distortion, especially with songs like Angel which has a ton of constant and droning bass.

So to fix your problem, here’s what I would do… (this is if it was me, I know you likely don’t have the shit to do this). I would zero the EQ controls and put an oscilloscope on the radio outputs and use test tones to find VAC the point of clipping. I would then build my signal chain and set the amp sensitivity based on that number and consider that the maximum I would ever turn it up to with 0dB tracks (and if this isn’t loud enough for your taste you need more power).

If you still have distortion, either the amplifier can’t handle the high level voltage and you need something from Audio Control or JL that has LOC functionality so you can use the low level inputs, (do not fucking buy some piece of Amazon dog shit LOC), or something is defective. You should be able to easily run with your high pass no higher than 80Hz (or even off) just fine if your EQ settings aren’t retarded and your gain structure is correct.

There should be nothing plugged into any input RCAs on this amplifier, the manual explicitly stated you cannot use both. I’m assuming this is because there is no selector switch.

 

With the high pass set around 180hz and the volume around 50 I am indeed able to turn the gain up considerably, settled on 1/4 turn on the gain. Kicker down firing sub box (50-500hz...more of a mid bass really) arrives tomorrow, dialing everything in should keep me busy for about 6 months. LOC may well be in the cards down the road.

On to new tiers (Geolander?), 100K mile maintenance.

Thanks everybody for the responses, hopefully someone finds this thread helpful.

 

Part of your issue may be speaker. Did I miss what speakers u have?

 

I've got the kicker KS on the stock HU and 50RMS amp; overall I'm happy with them. I have the crossover at +4db which I'm probably going to take down to 0db. Tracks like the opening guitar solo in Metallica's (hey the spell check knows Metallica...that's when you know you're big time!) "No Remorse" are wicked bright at loud volumes but that's kind of a bright mix I think, most stuff sounds really good and I think the sub box will round things out nicely.

I had the Infinity reference for a minute on the stick HU (no amp) and liked their "separation" and "detail" but the tweeters where intolerably bright all the time on everything.

I was actually driving today (rather then seeing how loud I can make things in a parking lot) and that found there was less rattling at volume and I could drop the high pass some more. Also I'm not exactly sure where I want the peek volume to be just yet, maybe around 45/63 on the volume control? So there's a lot more messing around and mirco adjustments to be done.

If I were to put more money into it I think I would buy individual tweeters and and mids and use the four channel amp as the crossover to really get control over the tweeter levels or maybe the infinity 3-way kappa and add a sub amp but that would be a $600+ project just for the tweeters and mids and at that point one really has to think about what's coming out of the stock HU.

Overall I'm happy especially for the price point for the majority of what I listen to (I'm currently seeking out the most challenging tracks at the loudest volume...without a sub) and would recommend the KS for the sale price, MSRP is a bit steep. I'd be curious to hear the Alpine S series but enough reviews mention too bright tweeters and the jump up to the R series is $400. I'm impressed that the KS survived my first stabs at tuning the amp, they defiantly took some abuse before I realized the difference between a 6.75" speaker and a proper sub.

Pretty much anytime I think about stereos I'm reminded of that Steve Martin bit from the 80s, cracks me up.
"Maybe it's the needle"