Help with setting the Low pass and high pass filters on PPI 900.5

[Chromatic]

Just want some general information of how to best setup the Low pass and High pass filters on the PPI 900.5 , 5-Channel Amp I bought.

Picture 3 of 8 for Precision Power PPI P900.5

Love how this amp has the HPF, LPF for all channels AND a LPF for the sub by itself it seems.

I'm running 6.5" components up front, 6.5" coaxials in rear, and a JL 10" sub 270watts .

Straight forward setup,.. off A Pioneer AVH-P4100DVD Headunit - AVH-P4100DVD - In-Dash Double-DIN DVD Multimedia AV Receiver with 7" Widescreen Display | Pioneer Electronics USA

The image above shows the amp settings.

My questions are:

1) I'd like to keep the lows the sub will cover JUST to the sub,.. and the highs and mids the other speakers will cover OFF the sub. So where would you set these filters? I assume the Front and Rear will be set similarly given they are both 6.5" mids and tweeters.

2) It's intuitive to just turn the screw to go up in frequency,.. but how do I know where I am in the frequency range? Never done this before. Do I play some special track or tracks while doing this and listen?

You get the idea.. it's a basic 101 question.. What's the best way to set these filters.. most amps I was looking at didn't have these built in. Mids/Highs have passive crossovers, but going from amp to set them as well should be a good idea I would think.

I'm setting the gains with 40hz sine wave on sub, and 1k sine wave for the rest of speakers. Got the tracks already,.. now how to set the LPF/HPF for front, rear and sub off amp and I'll be set on tuning this thing! In my mind I can only think of playing some type of track and turn knob until X frequency I'm playing stops playing or something similar .. as there isn't any markings to show you where you are at while adjusting.

I'm looking this stuff up on my own as well, just always get the best information from you guys.

Thanks

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[trumpet 5,000+ posts]

Set the LPF/HPF/FULL switches to FULL. Set your crossovers on the P4100DVD. All you need is high pass for the speakers and low pass for the sub, which this head unit should have built in. I recommend 80 Hz or 100 Hz all around.

I know this does not answer your questions, but it's how I would do it. It's more accurate and a lot faster than fiddling around with vaguely marked knobs that have no detents.

 

[Chromatic]

Set the LPF/HPF/FULL switches to FULL. Set your crossovers on the P4100DVD. All you need is high pass for the speakers and low pass for the sub, which this head unit should have built in. I recommend 80 Hz or 100 Hz all around.
I know this does not answer your questions, but it's how I would do it. It's more accurate and a lot faster than fiddling around with vaguely marked knobs that have no detents.

Well that helps... haven't noticed a HPF/LPF setting on my headunit.. but maybe it will present itself when I have the RCA's connected.

I just thought the amp's HPF/LPF and it has subsonic filter on it would be better than anything else .. I know it will be running through passive filters on speakers (and the sub has none of course).. but I figured it would be smart to utilize the amps somewhat "active" I Guess filters.

Do you not know how to set them off the amp "Accurately" using some sort of tones .. etc? Or are you just generalizing saying don't bother with it?

You can understand why I'd want to set them.. why not utilize them right? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif -- The goal is obviously to keep lows to sub... and mids and highs in their respective spots. The components and coaxials I'm installing have crossovers but they are "designed" to work without a sub.. they don't know I have a sub.. so They allow those low tones to the mids .. ie: 100hz and lower. Which I of course don't want on the mids since the sub will be handling such low frequencies,.. likewise I don't want the sub handling anything above 80-100hz .. (I've heard people who haven't a clue with their sub getting the full range and hearing muffled vocals and such trying to eek itself out of a sub lol).

Let me ask you this.

If I can figure out an accurate way to set them (I can only think using multiple tones.. maybe set up my laptop to the headunit Aux.. and play tones generated with Audicity in realtime of any Sine wave I want.. while adjusting those amp filters.. and when the tone stops coming through the speakers I'm adjusting I know I've hit that frequency.) That is the only way off the top of my head that makes any sense. Then I could just use a pencil or something similar and mark the crossover points, maybe making notation on the amp for future reference if I need to slightly adjust it as I am listening to "real music" .. days down the road, etc.

But again -- Is it at least "ok" to run the amps HPF/LPF and subsonic filters ON -- while also having passive crossovers for the mids/highs installed? Logically I can't see any reason it would make a difference, but just thought I'd ask. If it is fine, then I can try to figure it out myself .. and if I can't.. I can do what you say and basically set it all at 80-100hz where I assume Sub gets 100hz down, and Mids get get 100hz up (till their passive crossover limits the "highs".. and the tweeters get the rest.) Yeah?

Thanks for the answer nonetheless!

 

[trumpet 5,000+ posts]

Well that helps... haven't noticed a HPF/LPF setting on my headunit.. but maybe it will present itself when I have the RCA's connected.

Check the manual, it's there regardless of whether you're using the RCA preouts. You can turn the HPF on even when using the speaker outputs.

I just thought the amp's HPF/LPF and it has subsonic filter on it would be better than anything else .. I know it will be running through passive filters on speakers (and the sub has none of course).. but I figured it would be smart to utilize the amps somewhat "active" I Guess filters.

An active filter is merely electronic. Both the head unit's filters and your amplifier's filters are active crossovers. Your component speaker's passive crossovers are the other type of crossover.

Do you not know how to set them off the amp "Accurately" using some sort of tones .. etc? Or are you just generalizing saying don't bother with it?

You could use test tones and watch with a handheld SPL meter when the output drops 3 dB as you turn the frequency knob counterclockwise to try to come down to the frequency of your test tone. This is for setting the HPF. That's one way to figure out what knob position equals which frequency. If I had to use the amplifier's crossovers I would probably set them by ear, but I've done that many times. I stress that doing this on the head unit is the better choice considering your experience and the other equipment you have.

Do it for the experience? Sure, but I'm trying to save you any aggravation if you think setting the filters on the amplifier is superior.

.. and when the tone stops coming through the speakers I'm adjusting I know I've hit that frequency.)

The tones will not stop going through the speakers even with a high pass filter enabled. It merely attenuates frequencies below the crossover frequency. You're working with filters on a -12 dB/octave slope, so with the HPF set at 100 Hz the tone will be down 15 dB at 50 Hz. That's still audible.

But again -- Is it at least "ok" to run the amps HPF/LPF and subsonic filters ON -- while also having passive crossovers for the mids/highs installed? Logically I can't see any reason it would make a difference, but just thought I'd ask.

It makes a difference because the passive crossovers only take care of the mid/tweeter crossover. You need a high pass filter for the mids so they don't handle the bass.

 

[Chromatic]

Check the manual, it's there regardless of whether you're using the RCA preouts. You can turn the HPF on even when using the speaker outputs.

Did some digging,.. found an online manual.

And the headunit is dam.n impressive. It has High pass and Low pass filters,.. even Phase adjustments , (it has more than the amp has)...

But I can set the Low pass and High pass to one of the following frequencies (each):

50Hz—63Hz—80Hz—100Hz—125Hz

So.. set the Lowpass to 100, and Highpass to 100? Or would you go 80/80? Hrmm.

And.. I just read that using the High pass and Low pass on the Headunit AND the Amp simultaneously will mess with each other. So it's one or the other.

An active filter is merely electronic. Both the head unit's filters and your amplifier's filters are active crossovers. Your component speaker's passive crossovers are the other type of crossover.

Yeah, this is what I thought (I've had active before.. a dedicated active that is).. So essentially with this headunit I'm running active .. I'm just going to throw amp on "FULL" to cut off crossovers for Front and Rear speakers --

But.. there's an issue:

To refresh, here's a picture of the amp I have:

You CANNOT turn the Sub Low Pass filter "off" or to "FULL". I HAVE to set it. So,.. I guess I don't use the headunit for lowpass,.. and set the subs low pass (considering I sort of have to).

So now there's no avoiding. So just setting the Sub's Low pass filter,.. WITHOUT an SPL.. how can I do it? I mean, consider it drops X dB's.. that should be audible when I hit it right? The "volume" should reduce if I play say a 80hz sine wave,..? Then I know I'm at 80 (or 100.. if I play that).. Then I'm gtg on the LPF for sub.

Also,.. from that picture you see there's a Subsonic filter for the sub that has no OFF button,.. I must set it. It ranges from 20hz to 38hz. Where do I set this thing? And again, how? Should I just drop it all the way to left at 20hz.. and leave it be? Or is there some optimal setting? Why the heck have it if it doesn't do anything? Gimmicky? Regardless there's no off switch, so it has to be set somewhere.

So hook me up with (a method for) those two settings (Sub Low pass filter on AMP, and Sub "Subsonic" filter on AMP -- both must be set somewhere), and I'll set the front and rear mids/highs with the Headunit. (I guess at 100hz for the mids).

You could use test tones and watch with a handheld SPL meter when the output drops 3 dB as you turn the frequency knob counterclockwise to try to come down to the frequency of your test tone. This is for setting the HPF. That's one way to figure out what knob position equals which frequency. If I had to use the amplifier's crossovers I would probably set them by ear, but I've done that many times. I stress that doing this on the head unit is the better choice considering your experience and the other equipment you have.

I'm going to have to do it with the Sub LPF and Subsonic -- So need your help (I have ALL sine waves from 1hz to the highest frequency possible on a USB stick to play any of them.) I checked Home depot and Lowes to see if they had an SPL I could buy,.. use.. then take back (Cause they are like $100).. I don't normally do that, but come on. but, the only one is online only.. none in store. So looks like I'll have to do this some way without an SPL.

Do it for the experience? Sure, but I'm trying to save you any aggravation if you think setting the filters on the amplifier is superior.

I understand you. The headunit is direct select X frequency as I showed above.. and your done.. takes literally 5 seconds to push the buttons/screen. The amp I can see being a PITA to set.

But again, Sub LPF and Subsonic will have to be set on amp somehow.. I've been googling how to do it, and so far haven't found any 'guide' or anything.

The tones will not stop going through the speakers even with a high pass filter enabled. It merely attenuates frequencies below the crossover frequency. You're working with filters on a -12 dB/octave slope, so with the HPF set at 100 Hz the tone will be down 15 dB at 50 Hz. That's still audible.

Yup.. Makes sense.. But a 12dB drop should be an audibly lower drop even if it's still playing, no?

It makes a difference because the passive crossovers only take care of the mid/tweeter crossover. You need a high pass filter for the mids so they don't handle the bass.

I get it, master jedi //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif -- I need to cut out 80 or 100hz and up from the sub.. and 80-100hz and below from the mids (the passives will take care of the tweeters I'm sure, right?)

Thanks.. you are guiding me along.. so I don't have to jump on this forum mid install and post a "how do I do X on amp setting" and wait for some response that could take a day or two sometimes. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Side Show 10+ year member]

I use 80lpf and 80hpf

 

[Chromatic]

I use 80lpf and 80hpf

Sounds fair enough.. Still gotta figure out how to dial in 80hz on the amp (for the low pass on sub, as you can't turn it off).. And for that matter the Subsonic 20-38hz dial.. No clue where to put that other than maybe it doesn't really freaking matter.. . There must be someway to do this with just tones and an ear. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
The High pass can be turned off on amp,.. so I'll do that and use Headunit for High pass for front and rears.

 

[Side Show 10+ year member]

post pics of actual amp and wiring, and what you have everything set too.

 

[Chromatic]

post pics of actual amp and wiring, and what you have everything set too.

I did.. but again:

I wouldn't post pics of a different amp //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Yes,.. that's the amp. Yes, it says ST and 4CH (when it should have 5CH) .. yes, it's missing Crossover Band pass settings.. but that's what the amp, in my possession.. and ALL the 900.5 amps were labeled and made as. PPI mucked this amp up with switches and labeling,.. But it works as a 5 channel amp with clean power.

Other pics if you need:

Obviously you can't tell what anything is set to with the godawful X-over layout on this amp.. Note: Min and Max readings and a philips head to set it.. Couldn't get much more difficult unless it didn't have the min/max readings on it. This amp you have to dial in blind.

I used some math to figure out the stepping per "10ths".. and have approximated the settings myself,.. ie: Max Hz / 9 , then taking say min of 40hz adding that value, and stepping each value by said former value. If done right it equals the Max value on the 10th iteration.

Using this I have approximated within 1-2 percent each setting,.. installing starting tomorrow. From there I will go by DMM and ear where necessary.

Going to run Headunit Crossover of HPF, LPF and Sub crossovers WITH the amps Crossovers in tandem.. Will provide equal or better octave dB stepping at the X-over points.

As for where I'm going to run it.

Low pass I'm Crossing at 85hz.. for sub,.. Subsonic , the Owner of SRQ Customs who built my custom box said to set it at 20Hz (I trust the engineer/designer and builder of the box on this.) -- High pass I'm setting at somewhere between 80-100hz.. Doubt I'll overlap anything and probably go closer to 100 than 80 on the Highpass.

Thanks

 

[fasfocus00 5,000+ posts]

it's labeled correctly, ST stands for stereo as in 2 channel. it doesn't have 5 channel b/c it has a switch labeled EXT/INT for location of it's signal. EXT being external as in RCA input and INT as in internal for having pulled it's signal from channels 1-2 or 1-4. so this amp has 2 channel input, 4 channel input, or 6 channel input.

 

[Side Show 10+ year member]

you'll be missing a lot of midbass between the 80-100hz.

you set the lpf freq on the amp were it says LPF 80HZ..... did you buy the amp new?

 

[Chromatic]

it's labeled correctly, ST stands for stereo as in 2 channel. it doesn't have 5 channel b/c it has a switch labeled EXT/INT for location of it's signal. EXT being external as in RCA input and INT as in internal for having pulled it's signal from channels 1-2 or 1-4. so this amp has 2 channel input, 4 channel input, or 6 channel input.

No it's not labeled correctly. Will it function correctly, sure.. and that's all that really matters to me.

It's not EXT/INT,.. It's INT/SUB. I'll have that selector on SUB, so it utilizes the SUB RCA's. Semantics there, but since we are speaking of "labels" it's not EXT/INT. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

It doesn't have 5CH because they didn't put the label on the amp and the switch with 3 selections. I'm not making this up. The manual has 4 different amps in it,.. The last of them being my 900.5,. The End Panel's are very distinctly described for each amp,.. they aren't carbon copies of each other as the amps are all different.. from 1000.1, 600.2, 900.4 and my amp, 900.5.

Example: Input Selector Switch: "Choose ST for single stereo input. This allows the front and rear channels to receive signal from only the front RCA inputs. Chose 4CH for 4 Channel input. This allows for independent front and rear RCA inputs. Choose 5CH to use independent signal inputs for 5 channel RCA Inputs.

The amp has [sT-4CH] -- This is mislabeled,.. or more precisely, it is missing the third notch for 5CH and of course the 5CH label. The switch should be [sT-4CH-5CH].

But, placing it on 4CH,.. Having it on SUB, and having the 3 sets of RCA's in the amp will have it work in 5CH mode regardless. Haven't tested this, but I don't see any reason why it wouldn't. The amp comes with an output for a Bass Knob (which it has).. and the obvious RCA inputs for the Sub channel the reason it's 900.5 instead of 900.4.

And it's 5 channel, not 6 channel since we are talking specifics here.

Being general and what really matters,.. the amp will work as intended,.. it's not a big deal. The only function that is not going to work that it is supposed to have is Band Pass Crossover.

Rear Crossover Selector Switch: "Choose to activate the High Pass Crossover, Low Pass Crossover, OR Band Pass Crossover for the rear channels. Band Pass Crossover uses the High Pass AND Low Pass Crossover Simultaneously.

Again, another switch NOT included on the amp panel,.. The amp has a selector as you can clearly see that sas [LPF-HPF-FULL] and it SHOULD have [LPF-HPF-BPF-FULL] (Again missing a switch notch, and label). So should I have wanted Bandpass that this amp is advertised to have ,.. it simply is not available. Switching to LPF will only use LPF, switching to HPF will only use HPF,. and FULL is going to turn the crossover off. I can work around that, but some people want all the features advertised on the amp,.. someone hel.l bent on having both X-overs , using Bandpass would send this amp back and buy another companies amplifier. I am not, For my purposes it isn't necessary, plus I have redundant Crossovers due to having a very feature rich Headunit that has all Crossovers, independently for each of the 3 RCA outputs (Front, Rear, and Sub).

I'm not trying to be a douchebag here.. You were correcting me with your response.. I'm just restating my original statement and being very, very clear on why the amp is mislabeled. That said, I'm not worried about it in the least. If I were, I would have already sent it back.

I will say PPI's tech support is terrible. As in they aren't available, and do not return phone calls, voicemails, or emails after 2 business days. While this is minor in functionality, it is something a company with pride in their products would want to know and would fix in a revision to the amp on future production runs.

 

[Side Show 10+ year member]

*confused* so do you have the manuel for the amp?

not all 5 channel amps are set up the same, hardly any have bandpass feature

 

[Chromatic]

you'll be missing a lot of midbass between the 80-100hz.
you set the lpf freq on the amp were it says LPF 80HZ..... did you buy the amp new?

Well, everyone has slightly different preferences and recommendation. I'll be tweaking it as I go,.. and right now I have it somewhere around 85hz (can't be exact at the moment).. I will adjust the active crossover slightly between 70-100 to see what it audibly sounds like through a range of music,.. If the HPF needs to go down to 80hz,.. I'll definitely put it there. Thanks for the heads up though,.. I'll keep it in mind when tuning.

Thanks for the tip on where to set the Low pass.. I guess to be fair my initial post was "How do I set the Crossovers on this amp".. So thanks!

At any rate, I've worked it out before installing (Box is coming in tomorrow and I begin the install tomorrow afternoon/night) and have every setting , set VERY close if not exactly where it will stay from here on out. Of course I made sure the gains were to zero/Min as well,.. Those will obviously be tuned up with a DMM. I tinkered with the idea of grabbing a DD-1 -- I thought they were something major (As a local installer acted like having a DD-1 was something only "Pro shops" have,.. when For $150 you can get a very good DD-1 new,.. and used a fraction of that. I had figured they were considerably more expensive than that. They are in a price range that it is almost worth purchasing even with a 2-3grand system (That's pricing from a retail audio shop.. not buying and doing it yourself). But, I'm not going to burn the money.. I can tune by ear well enough and will be a bit conservative on the gains, further I'll set gains at Volume 30/40 = 3/4 = 75%.. I listen to this at 8-15 volume.. no more.

If you've been following any of my other posts towards the beginning of this.. This whole deal was to upgrade my 2, 10 watt factory speakers I have.. to something that sounded about like a factory premium sound system,.. I ended up with the equiv. of a $2000-$3000 System if I had these speakers, 5 channel amp, sub, custom box, etc done at any of the local shops here. Of course I spent $700ish,.. But I also have $500 pair of MB Quart Late 90's model Speakers on hand which lowered the budget considerably.. nonetheless it's a 6.5" Component set up front JBL MS-62C, MB Quart 6.5" Coaxial in the rears, Custom .66 Cubic Ft. Box with JL 10" Sub and PPI 5 Channel amp running it off a Pioneer AVH-P4100DVD headunit.

So it's going to be an insane upgrade from the 2 factory speakers running now,.. but lower on the bass, just the way I wanted it. My goal was just a LITTLE bass .. and I wrestled with 8" to 10" on the sub,.. but 10" was ultimately the right choice to make for a plethora of reasons I won't bore you with.

As for the amp. Yes, absolutely.. Brand spanking new. It's of good build quality, and I expect a nice clean output from it. It was recommended fairly highly on this forum, which matched up with the Price, Class D (Much cooler, and Much Smaller than another Amp I had in mind) was essentially the perfect amp for my application.

I figure Starting tomorrow (Fri).. I'll have this install wrapped up Sun night.. 3 days should be enough to tear down the interior of a 2 seater, install 4 speakers, sub, amp, and all the wiring of course.

 

[Chromatic]

*confused* so do you have the manuel for the amp?
not all 5 channel amps are set up the same, hardly any have bandpass feature

Yes, I have the Manual for the amp.. right in front of me as I just quoted it to the other guy who said I was wrong in my initial statement.

I understand not all 5 channel amps are set up the same,.. but this amp has Bandpass (well is supposed to) -- It's advertised on the front of the amp's BOX with Bandpass lol. The manual states it quite clearly, so this isn't a case of a misprint somewhere... It's just a quality control/design error in production. I doubt PPI will do anything about it.. They likely ran X units from China and that's that. Another model will replace this as is typical for amps... or most pieces of Car Audio equip.. they come out with another XYZ and this model is "discontinued" within a year or so.. give or take.

Again,.. The amp will very obviously function as a 5 Channel amp,.. If I pulled it out of the box and the Panel had Front and Rear RCA's and was missing the Sub RCA's, plus the Selector didn't have [iNT-SUB] , plus the amp clearly has a feature it doesn't on it's other multi-channel amps in a distinctly marked added Sub Low pass filter, AND a Sub , Subsonic filter/dial .. plus it has a "Bass Knob" ouput and included Bass Knob with like 16ft cord.. It's built right.

I'm not worried or concerned in the least about it operating for my needs just fine,.. The selector will just say "4CH".. but it's going to pull from the Sub RCA's for the 5th channel,.. I'll only be missing the Band Pass feature on the Rear speakers.. Something , frankly, I don't need -- I have a bandpass going with the Headunit being active on the rears as an active X-over if I chose to utilize the crossover on the Rears on the amp instead of putting the rears on [FULL],.

As for bandpass amps -- Just in this manual which has 4 amps of theirs listed.. their 600.2 has Bandpass, their 900.4 has Bandpass,.. and THIS amp (is supposed to) have bandpass.

This amp, likely, .. is similar to their 900.4 With the added 5th channel. Though the wattages are fairly different, so maybe the internals are completely different.

Everything's cool,.. I was just a little disconcerted when I pulled the amp out of the box new a few days ago and saw the panel.. but that initial concern was shortlived,.. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif