[jeffb335]

Originally Posted by kaigoss69

You may also want to try a 12dB slope between midbass and sub. That's what has sounded best for me up to this point. Both 80 and 60 Hz sounded pretty darn good...

Originally Posted by taibanl

Theres another possibility: The midrange may be suffering from mechanical rolloff @160hz. So the crossover filters while theoretically are summed to flat (which they should at 24dB) there is still missing spl.

I wonder if you would see the same results @200hz?

BINGO!

I raised my mid crossover frequency to 180 hz/24db, and changed the sub crossover slope to 12db, still at 65hz.

The 160hz dip is gone, bass is smooth and level all the way up and the sub level is also right on (it was a little high before).

Took a look at the iphone RTA and it looks pretty good (yes I know its not perfectly accurate, but it IS quite useful when troubleshooting). No glaring peaks or valleys, except for the high frequency peak that I partially put in there with the EQ, might just be the location and an inaccuracy of the crude iphone mic, reflections, cancellations, etc..... also likely my hearing is wasted .....BUT most important for the purposes of this thread, NO MIDBASS HOLE.





I think Im done with this experiment for now.....well done guys and thanks for the suggestions, now can we get some others to try this too!



.

[kaigoss69]

Right on Jeff, congrats on the success!

Now, did you also fold down the seats for calibration? If not, try that for much improved blending between sub and midbass. If you can't fold down the seats, put the sub in the back seat if possible!!!

[QUiKSR20]

Originally Posted by kaigoss69

Right on Jeff, congrats on the success!

Now, did you also fold down the seats for calibration? If not, try that for much improved blending between sub and midbass. If you can't fold down the seats, put the sub in the back seat if possible!!!

( Not thread jacking just asking about the iPhone App )

Im sure its not perfect but does that iPhone app help with troubleshooting and configuring the MS8?

I dont have a sub yet ( will next month ) but my midbass is lacking and I have been troubleshooting in my thread and changing calibrations a ton.

[jeffb335]

I thought I was done messing with this but the obsession never ends, nice quiet Saturday morning, how could I not shoot for a better MS-8 calibration....calibrated at -30, (seat down Kaigoss.) Similar results to above.....I think Ive got it as good as its going to get.....for now.....

[jeffb335]

Originally Posted by QUiKSR20

( Not thread jacking just asking about the iPhone App )

Im sure its not perfect but does that iPhone app help with troubleshooting and configuring the MS8?

I dont have a sub yet ( will next month ) but my midbass is lacking and I have been troubleshooting in my thread and changing calibrations a ton.

it certainly takes out a lot of the guess work and helps you know where to look....., as I mentioned a few posts back, my ears told me I was missing a narrow band of midbass, RTA app clearly showed it to be 160hz which was also my crossover frequency so that implied it was related to the crossover ......so I played around with it and quickly solved my issue.

itunes reviews on the app show its actually pretty accurate, guys have compared to to high end RTAs and found it tracks pretty well. Perfect? No....Good enough for casual use? Absolutely! From what I understand they sell a mic as well to improve the accuracy but for my purposes thats a bit of overkill.



The only thing that I find is odd.....the curve I got resembles what most people consider a good sounding curve (downward slope from 100hz on up, ending about -4db at the top) and my ears tell me its right, but it does not look like the MS-8 "target curve" as described by Andy. I dont see any of the low frequency +9db boost that he described.....yet, if I were to adjust it to get +9db it would sound terrible......what am I missing here? Is Andy using a different weighting when he describes the curve?

[mob17]

Sounds good, congrats.

Where do you place your iphone when doing the RTA? And im assuming you use the pink noise generated by the ms-8?

[jeffb335]

put it where your head is, just hold it, move it around your head, the curve changes a bit of course as you move it but if you have a real problem (midbass hole for instance) it will show up. I use a pink noise track on my ipod, through my dynavin head unit, that way I have the entire signal chain in there.....


As you move it around you will see things change a bit but you should be able to get a pretty good idea of if you are on the right track....
For instance, check out this one, even though the lower end is a little lumpy, the 1.25k - 10k is perfect, tells me the MS-8 is doing its thing just fine in that range, its the mid and lows that need a little more attention here.

[mob17]

Cheers i'll have a go with that with processing off and see what happens!

I might also try setting a LP on my amp, even though i don't have a sub.

At the moment i dont know if my mid bass sucks or not. I have only done one calibration so i guess i need to do more of these and then try doing the RTA. Just been a bit busy since i installed the Jehnerts.

[jeffb335]

Kaigoss,

what is the rational for doing the calibration with the seat down? I seem to be getting better results seat up....but I have an E92 so we may be dealing with a different set of variables here....

EDIT: Nevermind, just saw your post on the DIYMA thread, while I understand why its working better in your car, Im still getting better results with the seat up.

[el1818]

Attempt to try this but sadly my JL 900/5 doesn't have lpf for the underseat, only for the trunk sub.

[bmw325i]

Originally Posted by el1818

Attempt to try this but sadly my JL 900/5 doesn't have lpf for the underseat, only for the trunk sub.

This might be useful
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=266-258

[rcurley55]

I can't believe I missed this. I will try this out as well - but I have an E60. The issues should carry over because I have boomy subbass and no midbass after calibration. The sad thing is if I just take the trunk sub out and recalibrate, the system sounds great - go figure.

[kaigoss69]

Well I just did a pretty darn good calibration with the sub in the trunk, where it belongs! I went back to using a 24dB slope and with a 63Hz crossover point (thanks Jeffb335!). The KEY to getting good sub integration and good midbass is DEFINITELY the lowpass filter trick. I set mine at 200Hz, 12dB (MS-8 x-over is 160Hz, 24 dB). I set levels through the hidden menu, playing pink noise and measuring with the RadioShack meter. I ended up with the following levels at -25dB volume:

FL-Hi: 70dB
FR-Hi: 67dB
FL-Lo: 69dB (with amp LP enabled)
FR-Lo: 69dB (with amp LP enabled)
C: 70dB
SL: 71dB
SR: 71dB
Sub: 60dB (barely audible)

Post calibration, everything sounded great, and I did not have to touch any amp gains (first time ever)! I confirmed the MS-8 target curve which uses a +9dB boost up to 40Hz, and then slopes off to 160Hz, I believe. It was pretty darn close. I corrected a small dip at 63Hz with a 5dB boost through the EQ, and at 50Hz with a 3dB cut. DONE!

[mob17]

Well done!

Might be going slightly off topic so apologies. I was going to make another thread about db levels and calibration volume but it seems a bit relevant.

For arguments sake say your "sweep volume" is perfect for the ms-8. So should we try and adjust amp gains and/or calibration volume to ensure that the db level whilst listening to pink noise is roughly 70db for all speakers? So in effect have the sweeps at 70db? Or am i completely wrong?

Currently at -20db my un amped base rears play at 60db. Maybe this is because i use a completely different method of measuring spl; an iphone app. But say i had the same spl meter, should i try and get to 70db?

[kaigoss69]

^^^ I don't know! I calibrated at -40dB and I've never tried to measure the volume of the calibration sweeps. I'm not sure how important the calibration volume really is. I've had good results at many different settings. I think though the relative level between the different channels is key and that the sub needs to be set at 5-10dB lower!

In your case, that would be difficult to achieve since your rears are already at 60dB and 50dB is pretty much the ambient noise level in a car with the engine off. You can raise your calibration volume though to compensate, once you get your sub installed.

[mob17]

Ok, it was just a thought i had as there is a range of calibration volumes. Im just trying to figure out the relative spl of the sweeps that people generally use and are happy with. I always use -20db which outputs 60db in my set up.

You say you calibrate at -40db. So that should output roughly 55db during the sweeps i think (according to your 70db measurement at -25db). I may try lowering my calibration volume to -25db, to get 55db, and see if thats better. By the way, do you measure your underseats at head position?

Whats the reasoning behind calibrating at lower volumes? How should one decide what calibration volume to have?

Going to focus on my car audio from this Sunday onwards. Been neglecting it recently

[rcurley55]

Originally Posted by kaigoss69

I set levels through the hidden menu, playing pink noise and measuring with the RadioShack meter.

Can you elaborate on this or point to a post that does?

Thanks

[mob17]

He means that he ensured all speakers are level matched, so all roughly the same db on a spl meter.

Press left right left right each for about a second and you get into the test menu. Then select output identification, set ms-8 vol to less than -20db and then measure spl of each channel (either with a proper spl meter or iphone app). Adjust amp gains to make them within 2-4db of each other.

[rcurley55]

Originally Posted by mob17

He means that he ensured all speakers are level matched, so all roughly the same db on a spl meter.

Press left right left right each for about a second and you get into the test menu. Then select output identification, set ms-8 vol to less than -20db and then measure spl of each channel (either with a proper spl meter or iphone app). Adjust amp gains to make them within 2-4db of each other.

Thanks

[torqnDC]

I'll give this a shot this weekend. Only have a bandpass option for my underseat channels, but I'll set the low frequency crossover as low as possible and see where that gets me.

[tmac01]

So here are my settings and its just not cutting it with rock music sounds great with rap and r&b but not rock.

Jl Audio 600/6 channels 3-4 running Kicker mid bass LP is turned on and frequency is 200-220 I have it just a little over 200. The volume is set at 12 o'clock.

MS-8 Settings:

Sub
1. Subsonic filter 20hz
2. Subsonic slope 12 db
3. Sub/front/ Xover 70 ( I tried 65 as well)
4. Sub/ font slope 24db

Fronts
1. Front Lo/ hi X over 190 hz (tried 200,180,190, and 160hz)
2. Font Lo/ hi slope 24 db

Center
1. front Lo/ hi X over 190 hz
2 24 db

You get the point ! So what the heck is wrong I just can't get that ballsy sound especially kick drum. Now I do have my fronts channel 1&2 turned off on the JL amp which is what Kaigoss said to do he said let the MS-8 do all the crossovers am I correct there Kaigoss? Any more suggestions after reading my settings. Once again I can't thank you guys enough.

[tmac01]

Anyone ?