8 replies to this topic

[justdofit]

Apologies in advance for the long and n00b'ish question...

After completing my sub box, I'm looking into the next stage of my on-going build.

I've always wanted to put more work into the tweeter positioning in this car (the tweeters are currently mounted under the dash trim in the factory locations). And seeing some recent works on the forums I've been inspired to investigate building up some a-pillar mounts.

Not wanting to go through the build process more than once, I've also been contemplating the possibility of adding a set of mid-range speakers to the front stage (most likely the matching HL70 to the HSK165 set) while I'm at it? and building up pillars to accomodate these speakers and the current tweeters in one hit.

Currently I don't have the processing capabilities or additional amplifier channels to go fully active 3-way. But I do have the 2W.10 passive crossovers that came with the HSK set and a fair amount of power (imo) on my tweeter amp channels (~90WRMS ea).

Looking at the H100 section in the head unit manual & playing with the settings on the hu (with volume @ 0), it appears that if I change the 'TW SETUP' option from the default "MAKER'S" to the "USER'S" setting I can cross the tweeters (or in this case the passive crossovers inline with midrange & tweeters) at any of the pre-defined points between 20Hz~20kHz with the following slopes 6/12/18/24dB/oct. Am I right in assuming that the system will treat the 2W.10/HL70/TW25 as one speaker?

Below is the 2W.10 crossover diagram from the HSK manual - with the speakers swapped to suit the intended semi-active configuration. Unfortuneately I can't read these diagrams, perhaps someone on here can determine the crossover point?
I've read elsewhere that the HSK165 passive crossover point is 3.2kHz with 12dB slope (the same point currently in use with the active 2-way setup) - is this correct?



Also for reference, below is the diagram for the 3W.10 3-way passive crossover. As above I can't read these so I'm not sure where the crossover points are, and how this would differ from a semi-active setup using the 2-way passive crossover and H100 active crossovers.



If the 2-way passive crossover is not suitable, would moving the midbass onto an additional amp - and - using the onboard crossovers on the existing 4-channel to set a more appropriate crossover point between the midrange/tweeter be a realistic option? The current amp is a Clarion XH5410.

Also attached are the spec sheets for the intended speakers (TW25 & HV165 already in use).
TW25 Spec
HL70 Spec
HV165 Spec

My main question is if this is worth persuing and/or if anyone else has had success with this sort of configuration? Even if as a transitional stage to fully active 3-way?

Obviously there is always an option for more processing and additional amplifiers in the future - the main thing I'm wanting to avoid is building up some a-pillars for my tweeters and then re-doing them later if I go 3-way

Edited by justdofit, 03 February 2012 - 03:07 PM.

[Damon]

Since you'll be grouping the mid/tweeter, and since thier intersect point is less critical to tuning, it is totally feasible to power these from one pair of channels via the HSK165 set's passive network. The simply power the midbass from the other two channels. This way the HP/LP intersect between midbass/midrange can be set with the crossvers in the amplifier and you can play aorund with the fiolter point to suit your needs/power handling/stage height.

Easy peasy.

[justdofit]

Excellent, that's what I was hoping.

Thanks for the informative reply!

Looks like I just need to pick up a set of mid range speakers (HL70s) to start playing with 3-way.

Now to source a spare set of pillars from the wreckers and do some cutting to see what I'm working with

[jamiebosco]

FHRX has a set of the 3-way crossovers from the 'Energy' set on their Specials page for $100,not sure if they'd be suitable or not but they maybe worth speaking to Marty about.
Jamie

[justdofit]

Cheers Jamie

[TMM]

My knowledge of passive crossovers is basic, but from the first pic, assuming mid is 4ohm, tweet is 3ohm:

Mid:
-0.81mH inductor -> highpass 6db/octave 800Hz
-10uf cap and 2.2ohm resistor -> lowpass/highshelf 6db/octave 4kHz, resistor should limit this to -5db or thereabouts.

Tweet:
-6.8uf cap -> 6db/octave high pass ~3kHz
-0.3mH inductor -> 6db/octave high pass ~3kHz
-resistors provide attenuation
Effectively the crossover point is ~3kHz 12dB/octave. I'm just assuming the tweet is about 3ohm because that places the cap and inductor crossover points around the same frequency. If it were 4ohm the crossover points would be staggered (2.2khz and 5.5khz approx), i guess if this was the case it could be used to kill some brightness between 2.2 and 5.5khz.

My brain hurts trying to work out how the 10ohm resistor affects how the mid crosses to the woofer in the 3 way diagram.

If you were going 3-way active i would cross at 800Hz and 3Khz, 12dB octave and go from there. Try 18 and 24db/octave and see if it sounds better.

WIth the 2-way passive setup cross at 800Hz, again try all the different slopes and see which sounds best to you.

Someone with better knowledge than me feel free to correct

Edited by TMM, 04 February 2012 - 07:18 PM.

[justdofit]

Hi TMM, thanks for the detailed reply!

I will try crossing at 800 first and see how much lower from there I can go?

[Pulse-R]

The tweeter crossover is more likely to be around 5kHz (2x 3kHz @ 3dB each ~= 5kHz @ 3dB total)

800 is ok for a starting point, but you really want to get it below 400Hz for best results - if the midrange will take it nicely.
If the midrange starts to distort a lot, then you need a steeper slope, or increase the crossover frequency.

[justdofit]

Pulse-R, on 04 February 2012 - 08:14 PM, said:

The tweeter crossover is more likely to be around 5kHz (2x 3kHz @ 3dB each ~= 5kHz @ 3dB total)

800 is ok for a starting point, but you really want to get it below 400Hz for best results - if the midrange will take it nicely.
If the midrange starts to distort a lot, then you need a steeper slope, or increase the crossover frequency.

Thanks, I was hoping to cross the midrange at about 400-500 but I'll have to wait and see how much volume is in the pillars/pods and how the driver responds. 800 sounds like a good starting point and the go down by ear from there

Edited by justdofit, 05 February 2012 - 06:46 AM.