[DerAlte]

Originally Posted by nitrous

The user manual suggests tuning with the ears. This is tough for some less sensitive ears.

One can understand having to use finger-nails for turning the pot, but ears???

Sam, what is this? Shouldn't the manual writers at least check for implementability before suggesting?

[s0uljah]

Yeah these buggers tend to clip, Iv had it happen too. The heating issue seems to have been taken care of in the new design.

[Sam Kapasi]

Originally Posted by DerAlte

One can understand having to use finger-nails for turning the pot, but ears???

Sam, what is this? Shouldn't the manual writers at least check for implementability before suggesting?

No it says so quite clearly to use a screwdriver. It's tough to turn potentiometers with pinnae.

[sonic_boom]

Originally Posted by Sam Kapasi

I hope you understand.

Absolutely.
I was used to the fixed (80hz) LPF cut-off of my previous amp with no variable HPF. Thanx.

Originally Posted by DerAlte

Wasn't there a User Manual with the amp?

Guess I framed the query incorrectly .
I meant how do I set the gain for the sub and 6x9s independently cos it's hard to determine exactly at what point does the sound begin to distort with both the sub and speakers running.

PS : HU has only 1 pre-out

[amit_mechengg]

Originally Posted by s0uljah

Yeah these buggers tend to clip, Iv had it happen too. The heating issue seems to have been taken care of in the new design.

i too have heard from the dealers themselves that the new amp 104.4 doesnt have the heating issues. they said 75.4 used to heat up a lot and clip. but i asked couple of guys. they didnt face any such problem. even i havent faced any such problem till now, though i dont use it with full bass for longer times.

@sam / Navin sirs - can we put some cooling fans like the ones which we have in PC cabinets which run on 12volts DC by cutting the slots in the glass cover? can we get such voltages across the terminals given for neons?

[DerAlte]

Thanks, Sam!

Originally Posted by sonic_boom

... I meant how do I set the gain for the sub and 6x9s independently cos it's hard to determine exactly at what point does the sound begin to distort with both the sub and speakers running.

1. Start with both front and rear gains at min., and HU playing at a comfortable volume from your experience (don't you have speakers in the front???). Play known tracks with good bass content
2. Switch on HPF for the front channel of the amp, 80Hz on the Frequency dial
3. Increase gain of the front channel of the amp gradually till you get the desired "loudness"
4. Switch on LPF for the rear channel of the amp, 80Hz on the Frequency dial
5. Increase gain of the rear channel of the amp gradually till you "feel" the low frequencies from the sub
6. Increase the volume at the HU and check at what point you get a problem with the sub or the ovals - reduce the corresponding gain a teeny weeny bit at that point
7. If you are unable to make out whether the sub or the oval is causing a problem, do step 1-2-3-6, and then step 4-5-6

Originally Posted by sonic_boom

PS : HU has only 1 pre-out

Use RCA Y-cables at the amp end of the RCA cable coming from the HU.

[nitrous]

There is no markings for the frequency setting on the 75.4's panel.
So, I've set the front and rear filters to "flat". And Im using the HPF setting in the 6950 to split the frequency between the front components and the sub.
Btw, is it ok to set HPF of the 6" fronts at 63hz?
Or should I stick to 80hz?

[Bass&Trouble]

^^

nitrous, set the front comps to 80Hz. Your speakers have a low Fs and naturally play down quite low. By cutting at 63, you would send them much lower and strain midrange. But which is again fine if you dont listen to it very loud.

[nitrous]

Ok,thanks.
The "tuner" where I got it installed set the HPF at 125Hz and I got wild thinking "What is this? A Tweeter?" I lowered it more and more as soon as I left the shop and set it to 63. The front stage was superb and I couldn't feel the sub one bit.

[praveen_v]

When we add an amp to the system, we can set the cutoff frequency in two places. The HU and the AMP.

Which is better? and why??

1.Setting the cutoff in HU alone
2.Setting the cutoff in amp alone
3.Setting the cutoff in both HU and amp (wont this amount to filtering twice, rendering the filter in amp useless?)

I am talking of a system with the 75.4 amp. Also if my rear ovals are running off the HU, how will I increase/decrease the output from the rears so that I can maintain a front sound stage. I mean is there any way one can increase/decrease the output of rear coax driven from HU without having to increase/decrease the gain in the amp adjusting the fronts to get the effect.

[Autophile]

Do it from the Head Unit as the Crossover point is more accurate and the system is easy to tune. In case the HU does not offer the crossover function then adjust the crossovers from the amplifier.

[nitrous]

yeah, the HU's filters are digital while the potentiometer in amps are analog.
@praveen: U just need to use the fader control to move the soundstage to the front.

[praveen_v]

Originally Posted by nitrous

yeah, the HU's filters are digital while the potentiometer in amps are analog.
@praveen: U just need to use the fader control to move the soundstage to the front.

OK. setting the crossovers in the HU. then what about the setting in the amp? leave it at flat??

@nitrous, the fronts are taken out through the rca while the rears are connected through the speaker level out from the HU. Will the fader still work??

[nitrous]

then what about the setting in the amp? leave it at flat??

yeah!

@nitrous, the fronts are taken out through the rca while the rears are connected through the speaker level out from the HU. Will the fader still work??

Of course.

[s0uljah]

Originally Posted by praveen_v

what about the setting in the amp? leave it at flat??

Will the fader still work??

Yep you can leave the amp untouched.

Fader will work.

I prefer using the HPF 80hz on the HU for my comps and leaving the AMP as it is.