55 replies to this topic

[Matt VIP]

what should I try, proclass? reducing them both to 12db/oct slope? or overlapping the mid a bit higher?

That aside, I have made some major progress in the sound and hopefully in my understanding as well. when I had the mids in phase there was no harshness at 250-800hz, but out of phase there was. I had to reduce the EQ's in this area by heaps...

but then I tried reversing the phase on each of the mids (ie left normal, right reverse) and the harshness disappeared. EQ's came up, much better.

I havent really messed around with the mid-tweeter crossover point + slope much in the last couple of days, been mainly concentrating on the mid-sub(midbass) point. I'll have a mess around and see what it does...

thanks dude..

Matt

[~thematt~]

ProClass, on Sep 12 2007, 03:09 PM, said:

Is it just me? The underlap in XO points right smack in the middle of 3K explains the image issue. With 24 DB slopes this seems rather odd to me.
I would start with XO points and reduce slopes. It is my experience that 24DB slopes have proven themselves as a tough road with respect to image.

Seas Lotus tweeters, 24db 3.15kHz crossover

Boston Z6 mids running 24db, 63Hz - 2.5kHz crossover
cheers

I thought that was a bit weird initially too, but we moved on pretty quick!!

And I'm currently using 36dB/oct on my mids/midbasses and Ive found its sharpened the lower end of my image. Its also decreased 'stress' at higher volumes. Worked for me!

[Matt VIP]

what would your suggestions be, ~thematt~? and why does having an underlap around 3k with steep slopes affect the image? whats the technical reason?

[Damon]

I don't know if this has been mentioned yet but I thought it was worth adding.

The offset position between left and right speakers in a car environment creates both a TIME and INTENSITY imbalance. I'm mentioning this because the Pioneer time alignment system (on my P-80RS, I'm assuming you have the same unit) is a little tricky to set up.

This is because you must set the 'SEATING POSITION' function first to then allow the time alignment system to be activated.

Importantly, if you set the seating position to 'DRIVER' the P80RS will also adjust the balance level of the driver's side speakers to be louder than those on the passenger's side.

Make sure you begin with the driver position set for both front seats, then go into the crossover setting and check the levels for left and right to make sure they are set equally.

Once this is done you can 'push' the driver's side away to improve the arrival times. If the balance levels aren't sorted this can skew the results.

[Matt VIP]

awesome. thanks damon, however in order to access the time alignment you have to set the front seating mode to "driver" only. When I set the centre position for the tweeters i actually used a combination of decreasing the gain on the RHS tweeter and moving the balance until it more or less centered itself. However, using just the balance only, the whole image (when I put all the speakers back on) is skewed to the left by about 10-15cms from the middle of the dash. Just to check, I put on the balance test "bips" again, and sure enough, the "bips" were right over the middle of the dash.

weird...

anyway, we press on!

What are your thoughts on the P80RS unit damon, SQ and tuning wise?

[Damon]

Yeah, I knew there was the strange sytem where the seating position had to be set before the TA would work and this automatically adjusts the balance, but I wasn't sure exactly off the top pf my head if you had to have driver or front selected.

Aside from this stupid set up for the TA (which forces you to screw around with balance to readdress it) I really like my P80RS. The only other bug bear is the positive/negative display, which you can remove by again frigging around in sub menus.

I like the knob control system once you get used to to, and I find the iPod access quite fast.

All in all a great source that could be improved with a further pair of RCA pre outs to allow a 3-way crossover plus rear fill all at once ala HXD2. Still, for $849RRP it was the best value SQ soure on the market for a time. This mantle now goes to th CDA-9887 in my view.

[Matt VIP]

makes running a 3-way system with a sub a little tricky..

I'm yet to work out how my combination of JL slash amp crossovers, RCA pass throughs etc with the Pioneer HU will do it. Not that its a problem at the moment, as my subs are playing up to 200hz.

Anyway, on a more broader point, I'd just like to say a massive THANKYOU! to all those that have contributed to this thread! I'd like to think that I'm at a point now that I really need someone who knows stuff to have a listen and sort out some of the remaining problems. I think I've gotten almost as far as my ears will carry me for the moment : )

I'm MUCH MUCH happier with the sound however! The image exists, even if it's a little left-sided...I'm still not sure if inversing the phase of one of the mids is a good idea yet or not..the science is there, but the jury is still out until I can implement a proper 3way+sub system

So yeah, thanks MEA, hope to see you all possibly at wagga, and will endeavour to post pics of the trophy after the next comp

Peace

MAtt

[Pulse-R]

not wanting to throw a spanner in the works - but have you tried using a 12dB slope on the crossovers?

with the mids on-axis like that, I think it would work just fine.

and the Invisabass down to 100Hz.. to keep the harmonics out of the sound stage.

[muzzy66]

~thematt~, on Sep 12 2007, 09:17 AM, said:

And I'm currently using 36dB/oct on my mids/midbasses and Ive found its sharpened the lower end of my image. Its also decreased 'stress' at higher volumes.

Bastard!!

I must get a P90 combo one day...it annoys me that I cant go steeper then 18db/oct

Edited by muzzy66, 15 September 2007 - 11:10 AM.

[Matt VIP]

Pulse-R, on Sep 15 2007, 10:20 AM, said:

not wanting to throw a spanner in the works - but have you tried using a 12dB slope on the crossovers?

with the mids on-axis like that, I think it would work just fine.

and the Invisabass down to 100Hz.. to keep the harmonics out of the sound stage.

well the upper xo has been changed:

now at 3.15kHz 12db - 3.15 12db from mid to tweeter

and 200Hz 24db - 250Hz 24db from sub to mid

Pulse-R: I'm meeting up wth Sierra during the week for a quick test and tune one night, wanna come along?

i'm going to listen to it for about a week where it's at at the moment, then start changing it back to a more 2 way + sub system. see how we get on.

Thanks though!

Matt :clapping:

[Pulse-R]

sounds like a plan - keep in touch