9 replies to this topic

[s4turn]

Posted up on DIYMA, but also thought id try here with knowledgeable users on these boards!

curious to find out what other scanspeak 12m owners have these drivers crossed over at? LPF and HPF
mine are pillar mounted
http://i128.photobuc...rn/929d5a99.jpg
the reason Im asking is, I tested the Frequency response of mine last night (no HPF) and found they start rolling off around 4khz and these are mounted more on axis
(tested each side individually and summed)
looking at the spec sheet
http://www.scan-spea...12m-4631g05.pdf
correct me if im wrong, but in the chart they start rolling off around 6khz? at 30 degrees off axis


also a side question - after a quick RTA check on iphone, i Noticed I had 2 massive peaks in the 400 and 500hz bands, im assuming this has something to do with my pillars/enclosures? (I had them sealed before at around .3 L but now have removed these so they are venting into the dash)
would deflex pads or anything similar help tame this area without having to cut those bands so much? (midbass drivers turned off when testing this)

Edited by s4turn, 25 January 2012 - 11:11 AM.

[TMM]

You're using your iPhone as the RTA? well that's half the problem Have you tested the iPhone with other speakers? it could be mic in the phone causing the peak at 500hz...

Edited by TMM, 25 January 2012 - 04:15 PM.

[s4turn]

i've tested in the past when i had my founteks installed and it never peaked massively at 400-500hz, but yeah I will check again for a sanity check

[muzzy66]

Data sheet shows they roll off more like 5khz at 30 deg off axis. At such high frequencies for a 4" driver I'd say getting 4khz before rolling off is a pretty good result. Peaks coud easilly have to do with enclosures - I personally wouldn't want a driver like that venting out as it is, but even in a small enclosure resonances and all kinds of other phenomenon could cause such issues. What are they crossed at right now? I'd probably cross the Scan's no lower then 400hz myself, as they don't have as good low end distortion as the Fountek's do.

[s4turn]

tbh, the 12m's play much lower and cleaner than my founteks both FR88 and FR89's ever did.
I have them around 315hz? @ 18db/oct i think currently.

bit of an unfair comparison as the little founteks are 3" vs 4" 12m's (imho the founteks arent even in the same league as the 12m's, however for the price the founteks are a killer mid!)

the 12m's sound quite nice now, I was just worried about cutting the bands that much* in the 400-500hz region. (I was thinking of putting some kind of smaller deflex? pad behind the mids, as there is nothing there but bare metal! )
I did try them off axis, but on axis they just produce so much more detail and tonally sound great.

I know in the past, the founteks never had this problem in the 400-500hz region, however I had them mounted off axis, but still in the A pillars

[Big_Valven]

I'd definitely be adding mass to the metal behind them and treating reflections as a massive priority in this situation.

[s4turn]

any recommendations on the material to use? or would Dynamat be sufficient? I only need a very small amount to go behind the pillars

[BMWTurbo]

As BIg V said dampen your enclosure and immediate structure. Make sure you dampen the enclosure itself, you can try adding some eggcrate foam directly behind the driver, I have found this to work well in the freq region you are talking about.

[s4turn]

cheers, will give it a go

[s4turn]

thought id update this, the problem isnt really my enclosure or setup, its me
I need to leave things alone that dont need to be touched

i set my eq back to flat, and everything now sounds quite the opposite of what i did


(i am going to try dampening the enclosure though)