22 replies to this topic

[muzzy66]

I'd suggest you will most likely get best results with something like this:

Tweeter:
HPF: 4khz @ 24dB/oct
Position: Preferably up high, 30-45 degrees off axis
Notes:
I recommend 4khz as the optimal crossover frequency for the TN52's, and absolutely no lower then 3khz.

The tweeters have a large 12ohm impedance peak around 2khz (their resonance frequency) which doesnt smooth out until 3khz. Even crossing them at 3khz on a steep slope may not be enough to safely avoid the peak.

If you can get your midrange mounted at 30 degrees off axis, then you can get away with a 4khz crossover with good results. If you must mount the midrange more then 30dg off axis (or if it is out of sight) then I recommend sticking to 3khz to avoid the off-axis roll off.

I'd say you really wan't to stick with a steep slope on these - I wouldn't go below 24dB/oct. Going shallower, you will be more likely to be affected by the impedance peak, more likely to increase distortion, and also more likely to cause unwanted frequency overlap.

Reason I recommend a little off axis, is that the TN52's start to get a little nasty up high, with a 2.5dB rise beginning at around 5khz, and extending up until 20khz on axis. This would result in percieved brightness of the system. Running 30deg off axis should smooth them out enough to play flattish up towards around 14khz before beginning a soft roll-off. 45deg off axis would also neutralise the peakiness, however it would result in heavier (and earlier) high frequency roll-off - this would still be ok if you aren't too fanatical about extreme top end extension.

Midrange:
LPF: 4khz @ 24dB/oct
HPF: 300hz @ 24dB/oct
Position:
Somewhere forward (kicks perpaps?), where sufficient angle is possible. At 30deg off axis the 4" mids can play usefully up to 4khz. This is worth trying to preserve if possible, as the TN52 tweeters have weak low frequency performance.

The mid doesn't start to roll off in the bottom end until it gets down below 200hz. That said, it would be worth crossing it higher then this (300-400hz) for three reasons:
1) To optimise clarity (distortion will likely be significantly higher at 200hz then at 300hz)
2) To reduce enclosure requirements (it will probably need a good 2L of volume or more to produce clean, smooth output below 200hz)
3) The midrange has a 35ohm impedance peak at 150hz (resonance frequency) and you dont really avoid it until you go up to 300hz.

Midbass:
LPF: 300hz @ 24dB/oct (?)
HPF: 100hz @ 24dB/oct (?)
Position:
Optimally, the driver should be mounted in it's own enclosure - however in most cars you can't get enough volume to make a proper enclosure, so I'm assuming doors will be the intending mounting location.

Immediately, low frequency performance will be limited when mounted in the doors. Those midbass drivers don't product a lot of output below 100hz, especially in doors, so I wouldn't recomend crossing much below this (120hz would be better, but that may make tuning more difficult). I still recommend a 24dB slope because it gives the cleanest transfer from one driver to another with minimal peakiness and muddiness (due to driver overlap). However, I'm put a question mark here, because you may need to cross the midbass and/or sub on a shallower slope in order to help cover up the drivers limited low frequency output. Play around with different slopes and points and see how you go.

Subwoofer:
LPF: 100hz @ 24dB/oct (?)
Position:
Anywhere really, but centre of the car (i.e. middle of the boot rather then left or right side) is preferred as it gives more consistend distance between midbass and sub on the different sides of the car. This is more of a factor if you want a two seat stage (and less of a factor if you dont) but it might make tunign a little easier either way (especially time alignment).

That's about all I can offer at this stage - hope it helps

Edited by muzzy66, 25 July 2008 - 07:37 PM.

[bsyde]

Thanks whiteknight, silly me!

yeah i was planning to put the 4 in the kick. I have been reading alot about theories of tweeter in A-pillar with high Xover points and 4's in kicks. So that is the direction my trials are going to take me first off. thank you to Pulse-R for your advice

[bsyde]

And thank you MUZZY66 alot of helpfull stuff to think about. 100hz lp for the sub seems a little high, i thought 80hz and down would be a better place to start?

Edited by bsyde, 25 July 2008 - 11:00 PM.

[Juls]

I wouldn't pay too much attention to what muzzy says, he's looking at charts and computer software.. he doesn't own the speakers.. so it's still guessing based on techincal data.. which seldom shows the whole picture. and rarely allows for cabin gain. While I respect what he's saying and understand the technical reasons behind what he's saying. It's not real world experience.

I tried running the TN52 to the 100KP active for a long time,
but never managed to get them to sound as nice as when you just use the supplied crossover.

in the end I ended up running the 100kp with the TN52 on it's own x/over at about -5db setting on the x/over roughly. (stock x/over is 3.5khz 12db, this works perfectly fine) then run active from the 100kp to the kbe driver.

I run the 100kp in roughly a 1 litre sealed enclosure,

I run my 100kp HP at 250hz 24db,

the KBE/K3p Driver I run at LP 280hz 24db, and High pass at 63HZ 12db (the KBE can handle MASSES of power at that crossover and placed low in the doors still happily pumps out frequencys in the 50hz region even with that crossover point)

I run my 33KX at 71hz 24db x/over. (a 40 won't fit in my ute.. at least not in a ideal fashion anyway othwise i'd probably run that)

You'll note I use a mix of 12db and 24db cuts, I'd suggest you stick to that arrangement,
keep out of the 6's 18's and 30's.

in my car the midbass is very strong, the midbass hits are high on the dash and sound very central, theres no pull back or pull left or right, it comes out as cleanly as the voice imaging.

every car is different so the x/over points you will need will vary somewhat.

Don't be scared to run a 12db 60-80hz cut on your KBE. Most speakers will die a
painful death with any power applied to them with those types of crossover,
but the KBE handles it with ease. doesn't break a sweat even in the toughest goings on.

This being said I wouldn't suggest running them full pass, as you might bottom them out with 30-40hz work at Very Very high volumes. (however most other speakers will be dead long before the kbe in that scenario) a 12db cut provides just the right amount of protection from those frequencys without cutting them out alltogether. Helping supply you with up front and well imaged bass.

Running a 100hz 24db high pass cut on the kbe is nothing more than a joke. And simply
ruins this excellent midbass driver.

I have had experience with other top of the line drivers from Boston, Alpine, MB Quart, Dynaudio, scanspeak ect ect all of which can't take that kind of x/over without bottoming out and destroying themselves fairly quickly at high volume levels. Hence the need for drastic 24db cuts when using many other drivers.

my 2c.

Juls

[bsyde]

Thanks for your thoughts juls, i am taking it all on board. I bought all the speakers as raw drivers planning to go active, so i dont have xover. I will have enough processing to get good results i think. I know how hard the KBE's hit since a system i did at work a lil while back and vowed that i would one day have a set of my own. I was almost happy with that system without the sub. I have another few months to ponder on my system untill i get my new car, so keep the ideas and thoughts comming

Edited by bsyde, 07 August 2008 - 05:50 PM.

[Juls]

bsyde, on Aug 7 2008, 03:46 PM, said:

Thanks for your thoughts juls, i am taking it all on board. I bought all the speakers as raw drivers planning to go active, so i dont have xover. I will have enough processing to get good results i think. I know how hard the KBE's hit since a system i did at work a lil while back and vowed that i would one day have a set of my own. I was almost happy with that system without the sub. I have another few months to ponder on my system untill i get my new car, so keep the ideas and thoughts comming

no worries.

with the x/over point on your 100kp to the tn52, it's going to depend how far away from each other you mount them, in regards to what kind of slope you can use,
if you mount the midrange exactly next to the tweeter, you might be able to get away with 24db slopes, but if they are separated, then more often than not you need to use either a shallower slope or use more overlap. The same really goes for the 100kp and the K3P, I run my 100KP directly above my K3P driver in the door, then the tweeter up on the dash a pillar. (firing at the headrests) my 100kp is also firing from the mid forward section of the doors to the headrests on the seats. so technically my left hand tweeter and midrange are directly on axis with my head in seated position. and are equal distances away as well. (for time aligment sake)
My midbass is mounted flat against the door (off axis) as low and forward as possible.
I did run the midbass on axis/semi on axis for awhile, but you don't get the low bass cabin gain. It just sounds 100% better off axis in terms of bass capabilitys. Obviously if you had a 2 way set instead of 3 way you couldn't do this as successfully since being off axis would be detrimental to your midrange/midhigh freqs.

Juls

[muzzy66]

Juls, on Aug 7 2008, 04:38 AM, said:

I wouldn't pay too much attention to what muzzy says, he's looking at charts and computer software.. he doesn't own the speakers.. so it's still guessing based on techincal data.. which seldom shows the whole picture. and rarely allows for cabin gain.

Question:

How much effect will cabin gain help a speaker that is 3dB down by the time it reaches 80hz?

Think about that one, and get back to me.

Quote

I tried running the TN52 to the 100KP active for a long time,
but never managed to get them to sound as nice as when you just use the supplied crossover.

Maybe you could have, if you tried my recommended settings (joke)

Quote

in the end I ended up running the 100kp with the TN52 on it's own x/over at about -5db setting on the x/over roughly. (stock x/over is 3.5khz 12db, this works perfectly fine)

Funny, that sounds surprisingly similar to the crossover point that I recommended based on my 'charts'.

What an amazing coincidence!

Quote

the KBE/K3p Driver I run at LP 280hz 24db, and High pass at 63HZ 12db (the KBE can handle MASSES of power at that crossover and placed low in the doors still happily pumps out frequencys in the 50hz region even with that crossover point)

Yes, it can handle power at 63hz...however it won't produce good output at 63hz.

At around 100hz those midbass drivers will already begin to roll-off, resulting in a gap of some degree between midbass and sub if you cross lower then this.

I'm famillar with the 6K2P not only specs-wise, but also in person - I did a lot of back to back listening with those speakers against a good degree of other high end ones in a well controlled environment. Indeed, they produce better midbass then any other component set I've head, but they are still only effectively usable down to 80hz at the most. Even at an 80hz crossover point, there is a noticable gap in between it and the sub. The bottom end output doesn't vary that much between the K2P and K3P driver...the K3P has slghtly more extension, but it's not by as much as most people seem to think.

You think just because you can 'hear' 50hz frequencies coming out of the mids, that it means they are good to be run that low? Contrary to what you may think, either of those drivers will be down by at least 3dB by the time you get to 70hz - at 60hz they will most likely be about 4.5dB down or so (rough guess) and by 40hz-50hz your're absolutely wasting your time because half of your low frequency information is lost.

Quote

every car is different so the x/over points you will need will vary somewhat.

The car doesn't determine your suitable crossover points...the placement/install/angle of the drivers determines suitable crossover points. Angles of mids determine where they will roll-off, and hence where you should cross them over (as you want to cross them to play within their effective range).

Put the same mids at the same angle in different cars, and the recommended crossover point will be the same.

Quote

Don't be scared to run a 12db 60-80hz cut on your KBE. Most speakers will die a
painful death with any power applied to them with those types of crossover,
but the KBE handles it with ease. doesn't break a sweat even in the toughest goings on.

Why?

That's lilke saying "don't be afraid to run a 12db, 2khz cut on your TN52s".

Sure they'll handle it, but you'd be wasting your time because the output below 80hz will be too low to be of any use...

Quote

Running a 100hz 24db high pass cut on the kbe is nothing more than a joke. And simply
ruins this excellent midbass driver.

If you are going to make such a blatant statement, then at least offer some form of justification.

Let me put it simply for you:
* The Focal midbasses will begin to roll off at 100hz at least (if not earlier) no matter what enclosure they are or are not in (unless if it's vented).
* If you cross your sub over at 80hz, you will have some degree of gap (degree depending on how far down it is) between your midbass and your sub.
* Gaps in response sound bad - you will miss out on musical information below 100hz unless you 'band aid' it by using a shallow slope, in which case youll cover the gap and muddy up your sound in the process.

All of this is ASSUMING that you are running that midbass in an enclosure designed for the best possible bottom end extension - which car doors are NOT.

Not sure if you recall, but one member on this site actually ran his K2P drivers in his doors, and then ranthem a second time running in door mounted enclosures. He took physical measurements of both cases, and not only did the 'door' mounted install result in nasty midbass resonances, it also resulted extreme roll-off below 120hz to the point where below 80hz the output of the speakers' was all but useless. By comparison when he mounted them in the doors the resonance was gone, and the extended FAR lower.

In fact guess what - I just remembered I actually saved the graph he posted at the time (with his permission), so here it is (my apologies for not properly crediting him, as I forgot his username ("powerband" or "powervan" ring a bell, but not sure).

Take a look at the response of the 6K2P's in doors, and then tell me if you still recommend running them below 100hz...

And this are not 'charts and computer software' it's actually real world measurements that the person took of his system.

As you can see, the K2P mid was actually a full 10dB down at 80hz when mounted inside the doors (3dB down when in enclosures). I personally guarantee you that a simple 1mm or so increase of xmax (that the KBE has over the K2P) will not translate into 10dB more output at 80hz then the K2P...however it would have to produce AT LEAST 7dB more output at 80hz to make it even remotely useful at that crossover point.

Also, notice that the measurements taken of the K2P's bottom end in the enclosure pretty much perfectly matched my earlier predictions (which were a roll-off beginning at 100hz, 3dB down at 80hz and 4.5dB down at 60hz).

Surprised? I'm not!

But hey, "pay no attention at all to what muzzy says, as he's just just looking at charts and computer software".

Attached Files

•  enclosure_door.jpg   331.61K   1 downloads

Edited by muzzy66, 11 August 2008 - 02:11 AM.

2004 Alfa 147 Twin Spark (Phase 1)
Source: Clarion HX-D2
Tweeter: Scan-Speak D3004/6020-00
Midbass: Scan-Speak 18W/8535-00
Speaker Amp: Tru-Technology Billet B-475
Subwoofer: Peerless 830877 XXLS 12"
Subwoofer Amp: Celestra VA210

1998 Ford EL Fairmont
Source: Eclipse CD8455
Tweeter: Scan-Speak D3004/6020-00
Midbass: Peerless 831882 HDS Exclusive
Subwoofer: Peerless 830846 XXLS 10"
Amp: Helix HXA-500

• Back to top

[Arnold Swollenmember]

the 165 kbes sounded good when in the doors at 36hz and -12db slope, was quite surprised that there was still a decent response. personally i usually run it at 50 with -18 slope but the sub is out most of the time due to a pram