Processor Question

jay27

I have heard of people using a DRZ9255 with a BitOne processor. My question is this: At what point is the sound dictated by the processor rather than the head unit? In other words, could you connect the BitOne to your average $200 head unit and get the same sound as a with a $1400 head unit? If a head unit is being used solely as a transport (as in the scenario above), does it matter at that point which head unit you ultimately use?

MacLeod

Some people think that the $4000 head units have a better laser or some **** and somehow transmit the 1's and 0's better than a $400 head unit. I used a $200 Alpine head unit for competition and switched to the $500 9861 only to get the optical output. The only difference in sound was the lack of noise with the optical.

Thats not to say you can run out and grab a $50 Kraco from Autozone, you still need good quality gear but there is a point where you aint gonna hear a difference. For instance, .4% THD is more distortion than .04% THD. Doesnt matter because you cant hear anything below 1% anyway. Same thing here.

The only reason I would use a much more expensive head unit would be for tuning features. The top end Clarion and the new Eclipse have great time alignment and crossovers so you could use the head unit for that and then an external EQ like the Audiocontrol DQS.

The Bit-1 has everything so all you need is a good solid head unit to act as a source and the processor will take the source and do the rest.

jay27

Thanks a lot for the information. Now I just need to find out which head units actually have optical.

MacLeod

Any head unit that is a DVD player will have an optical output.

For Alpine, any head unit that starts DVA is a DVD player.

cadenceclipse

don't need dvd for optical

jay27

When you use optical, does the preout voltage from the head unit still matter?

cadenceclipse

yeah

MacLeod

cadenceclipse wrote: »

don't need dvd for optical

Never said you did but 95% of CD players DONT have optical outputs where 100% of DVD players do.

And no, pre-out voltage has no effect whatsoever on the optical output signal. The pre-out voltage only matters if youre going to use the RCA outputs which you wouldnt be using if youre using the optical output.

cadenceclipse

true, true. we're a rare breed mac

i thought he was asking if optical cancels the need for a nice preout. but macs right

arun1963

And no, pre-out voltage has no effect whatsoever on the optical output signal. The pre-out voltage only matters if youre going to use the RCA outputs

I think thats becoz with normal rca's there would be a voltage loss from hu to amp the wires resistance. So say a 5v from the hu would mean amp gets the signal at say 4v. Numbers are for ref only. I dont remember the formula from high school physics. Hence higher preout voltage is preffered.

With an optical out, a light beam is travelling through an optic fibre. 0% loss.

Mac: Does one optical out get split three ways for the sub, mid and tweets at the amp?

arun1963

hang on, the optical out would connect to a processor that would convert the light signal back to current and split the signals, right?

MacLeod

You got it.

The entire audio signal from 20-20 KHz is sent down that little fiber optic tube. The processor takes it and processes it then runs it thru its DAC then out thru the appropriate RCA's.

thechooky

Anyone know what the response curves and cross over points that are appropriate MM6500 series speaks on an active system??? What is a good sig generator and wideband SPL meter for determining true flatline non-corrected response curves (installed speaks of course). It seems as if POLK doesn't like to publish benchmark THD vs SPL curves anymore (KILL the marketing peeps please). I just need to know the XO point so I dont trash my speaks when I go active and toss the passive junk (read in crossover).

Also what is the diff in impedance between the mid-woof and the tweet. I will drive those expensive little guys using a 4ch 100watt (123 benched @ 1Khz using an HP scope from the 80's) Alpine. Besides lowering the gain, via the Alpine DSP before the amp, I like running my amps with the gain all the way down. Though this could still be too hot for the tweets, so do I need to put a load resistor in parallel to prevent smoked silk??? If so, I would rather like to find a good class delta 2ch with a lower RMS, because I hate inefficiency...

I am an electrical engineer who is too tired and lazy once I get home at night to figure this out. If anyone would help me out and knows this info off the top of their head, I would be very thankful. This stuff is just too expensive for trial and error.

thechooky

MacLeod wrote: »

You got it.

The entire audio signal from 20-20 KHz is sent down that little fiber optic tube. The processor takes it and processes it then runs it thru its DAC then out thru the appropriate RCA's.

If anyone treasures true digital to the processor, then stay away from the new Eclipse 2din nav unit. The 726e doesn't have any sort of optical out. In fact, the little demon doesn't even process DTS!!! Thats right, chunk over more than 1500 big ones and you can't even play Hell Freezes Over the way it was supposed to be listened to along with many other live, concert DVD's. You have to settle for some poorly down mixed stereo (16bit 44khz as opposed to 24bit 96khz studio DTS track) track over noisy rca's. Although I can't really hear the noise or distortion, dammit I know its there, right. Plus I hate the fact that once my lowly 5v signal gets to my alpine processor (HUX701), it has to be reconverted to via an ADC.

If anyone would like to have a gently used eclipse, just dumpster-dive my trashcan next week. I'm going AVIC110 (Pioneer). And yes, I cant say that name in plain syntax, it just hurts too much to leave eclipse after all these years.

arun1963

I am an electrical engineer

Maybe that explains why you're overthinking it a bit. That's cool, I do it all the time and I'm not even an EE.

1. Are you referring to the new MM6501 or the older MMC6500 momo's?

2. The mids and tweets are 4ohms each, on both the sets. Both drivers will handle 100-120rms as long as you set the gains properly. You want the amp to max out its power once it sees the max rms volts from your hu. Decent hu's do this at around 80-85% of max volume. Hence, set the volume at 80% and play with the gains till you hear distortion. Then turn the gains back a bit. If you set the gains at a position other than this, you're either underachieving or driving your equipment too hard.

3. Response curves are normally measured in 'ideal' conditions (speaker in a sealed box in a real room). The minute you put the speakers in the doors, whole new ball game. The only numbers of value would be the roll off points of the drivers which is basically the freq range of the driver. If you want to balance frequencies for L/R and then level match them, you will need a test tone cd and a spl meter.

I run my momos in an active setup and my sub and mids are crossed at either 50 or 63hz (depends on what I'm listening to) and the mids and tweets at either 4 or 5khz. Everything except the tweets are on a steep/est slope.

cadenceclipse

2.7 on mm6501, no? not 4 ohm

unrealii

cadenceclipse wrote: »

2.7 on mm6501, no? not 4 ohm

Yup mm6501 is 2.7 ohm. Tweeters are almost 4ohm, but through the crossover with the mids the system comes to 2.7ohm. I forgot the exact numbers, I measured these about two months back.

thechooky wrote: »

If anyone would like to have a gently used eclipse, just dumpster-dive my trashcan next week. I'm going AVIC110 (Pioneer). And yes, I cant say that name in plain syntax, it just hurts too much to leave eclipse after all these years.

Why wouldn't you go with an alpine hu? I was looking at hu's a few months back and they seemed to integrate very well with their processors.
Read up on the pico fuse issue with pioneer then now eclipse doesn't seem too bad

thechooky wrote: »

Anyone know what the response curves and cross over points that are appropriate MM6500 series speaks on an active system???

Setting the tweeters at 4khz @ 18db then blending the mid seems to work well for me. It also worked well for my buddy's non-polk 6.5" component system (forgot the name).

lee258

:d:d

GuitarCrazyo

Ok so anyone have experience reselling to NON US companies?

Not easy to find a MSP or payment processor that has agents/resellers and provides for NON US companies..

Any leads to which merchants would be good.

Thanks

bigaudiofanatic

MacLeod wrote: »

Some people think that the $4000 head units have a better laser or some **** and somehow transmit the 1's and 0's better than a $400 head unit. I used a $200 Alpine head unit for competition and switched to the $500 9861 only to get the optical output. The only difference in sound was the lack of noise with the optical.

Thats not to say you can run out and grab a $50 Kraco from Autozone, you still need good quality gear but there is a point where you aint gonna hear a difference. For instance, .4% THD is more distortion than .04% THD. Doesnt matter because you cant hear anything below 1% anyway. Same thing here.

The only reason I would use a much more expensive head unit would be for tuning features. The top end Clarion and the new Eclipse have great time alignment and crossovers so you could use the head unit for that and then an external EQ like the Audiocontrol DQS.

The Bit-1 has everything so all you need is a good solid head unit to act as a source and the processor will take the source and do the rest.

I agree with this, it gets to the point when it is like okay that is nice but do you need it? The answer is no. Also unless your music is uncompressed and coming from the original cd or from a lossless format than all that will be worthless.