SQ: Which amp? I am down to 3 choices

Thunderplains

Alright, after much research & time, I have narrowed down my system..
I picked up the Audison Bit One processor and I feel after much debate,
That I am going to stick with the SR series (6500 in front, 124DVC in back)
The last thing on my list is the Amps.. I have heard and read WAY too much, and I woud like to get this right the first time out the door..

I have already started fabricating the trunk, and I am at a point where
I have to make a choice AMP wise.

My Original selection is the POLK 500.4 (bi-amp SRs) and 1200.1 to drive the subs at 1ohm, price is good and I have not yet heard anything bad

I am also looking at Audison LRx4.1K (2) to power everything, but I am getting way out of my budget.

I was also told to look at Zapco as well, although I am not sure what model.

I still am leaning towards the Polk, even though the latter seems to have a better THD documented..

So any help with direction on making a AMp choice would be appreciated. I plan to slowly get into SQ comps, So I want a solid setup going in the door.

Thanks.

MacLeod

All of those are excellent amps. Im using the Polk 500.4 to bi-amp my SR6500's and a 1200.1 for my single SR124DVC. Ive used them in MECA SQ competitions for the last 2 years and have had good results.

The Polk's dont have the "oooh and ahhh" factor like Zapco and Audison but they sound just as good. A watt is a watt and so long as the amp is well built, cleanly makes and even exceeds its ratings and most of all is noise free, thats all you want and all of those amps will do all of those things.

arun1963

+1 for the polk 500.4.

I would look at the genesis ultra 4 (4x100watts) before I looked at the audison. But like mac said, the fancier amps dont put out better sq. They are good amps but you're paying the extra $$$ to a large extent, for the brand name.

Good sq is a combination of several factors. Equipment is one. Equally important is stuff like install, damping, tuning etc.

tk421

buy the cheapest of the three.
-install accounts for 75% of your time and money.
-25% is equipment.

jay27

I have Zapco amps and am considering switching them out for some smaller ones for an easier setup. I am not yet convinced that one amp sounds better than any other given that they both have the same power. I plan to a/b test the Zapco amps with some new digital ones and see if there is any difference between the two.

jay27

MacLeod wrote: »

All of those are excellent amps. Im using the Polk 500.4 to bi-amp my SR6500's and a 1200.1 for my single SR124DVC. Ive used them in MECA SQ competitions for the last 2 years and have had good results.

The Polk's dont have the "oooh and ahhh" factor like Zapco and Audison but they sound just as good. A watt is a watt and so long as the amp is well built, cleanly makes and even exceeds its ratings and most of all is noise free, thats all you want and all of those amps will do all of those things.

MacLeod: When you say you bi-amp your SR's, are you using the passive crossover in your setup or did you discard the passive crossover altogether? The manual for the SR's show the passive crossover being used when bi-amping.

Thunderplains

jay27 wrote: »

MacLeod: When you say you bi-amp your SR's, are you using the passive crossover in your setup or did you discard the passive crossover altogether? The manual for the SR's show the passive crossover being used when bi-amping.

I was about to ask that next as I was wondering if you run them directly into the AMP and let the processor do the work or not.

Processors, that's another story.. I finally gave into the Bit One, I like it's flexability and management. But as far as tuning, I feel it has mor features than is needed.. I'll just shut off the DSP on the DNX9140

MacLeod

tk421 wrote: »

buy the cheapest of the three.
-install accounts for 75% of your time and money.
-25% is equipment.

Actually its more 55% tuning, 25% install and 20% equipment.

When you say you bi-amp your SR's, are you using the passive crossover in your setup or did you discard the passive crossover altogether?

I run the head unit signal via optical cable to my Alpine H700 processor which splits the signal up then out to the amp.

arun1963

MacLeod wrote: »

Actually its more 55% tuning, 25% install and 20% equipment.

very true.




@ Thunderplains

But as far as tuning, I feel it has mor features than is needed.. I'll just shut off the DSP on the DNX9140

Use all the tuning tools at your disposal with the bit 1. This will allow you to 'hear' the the true potential of your equipment/install. Run a digital signal from your hu to the bit one. I checked the kenwood site for you dvd hu and you would be better off bypassing all audio control from the hu and doing the audio settings from the bit 1.

Thunderplains

Digital signal will not be happening on the DNX, no coax or optical.. So I will have to stick to the 2 fronts and 2 sub outputs. 5v RCAs, but that is the best I will have to do.. And yes, bypassing the kenwood audio control is the plan..

Looking back at the posts, since I am bi-amping the SRs, will I need to use the passive X-over that ships with them, or let the Bit1 do the work?

Also, on the PA amps, how should I set the switches/dials? So from a tuning perspective, everything will revolve around the Bit 1, yes?

MacLeod

Use the Bit1 for everything. Put the passive crossovers up on a bookshelf for display cause theyre pretty damn cool looking.

Id set the gains of the amps to around 10:00 and use the processor to adjust level outputs. Leave the crossover and bass boost off on all the amps.

arun1963

If you set everything from the bit-1, you can ditch the xovers and go active. If you were setting it from the hu you'd have to use the xover. I dont think the hu supports active mode.

Yes, you would tune everything from the bit1 and bypass all lp/hp at the amps. The only thing you'd set at the amps, would be the gains.

arun1963

Mac, you posted while I was typing....;)

Thunderplains

Sweet. Just wish I had digital output from the HU.. Oh well..

Any feedbac on the RF 3sixty.2? This was my first choice..

MacLeod

From a competition standpoint it aint the best. The time alignment is in something weird like .13 ms increments as opposed to the .05 increments of the Alpine. Also the sub crossover wont go below 50 Hz which aint a problem for daily driving and listening but is for competition. And it is only 4 channels so if you want to run a 3 way setup youll have to figure something else out. Then there is that whole delay when you adjust something on your Palm and the time it takes for the 360 to actually make the change.

arun1963

Mac, is there a formula for converting the 'ms' to 'inches' used on the pio units?

MacLeod

This isnt a formula and I dont really know if there is one. Im sure there is but Im not smart enough to know it.

This is out of my Alpine 9855 owners manual.

http://www.fixya.com/support/p198869-alpine_cd_player_cda_9855_limited/manual-2090/page-21

bigaudiofanatic

I would go with audison I have had one of there amps before and there simply amazing.

MacLeod

If you can afford them.

arun1963

bigaudiofanatic wrote: »

I would go with audison I have had one of there amps before and there simply amazing.

If you're going to spend that kind of $$ on an amp (beyond a point, personally I would always spend extra on speakers rather than amps) then I would look at genesis amps over the audison. The profile ultra 4x100w rms beat the Audison LrX 4.1 in a pure a/b test I did while testing both Morels elates and the dyn esotec. Like all high end british amps, the profile ultra is very neutral with excellent speed, clarity and presentation across the mid bass/mid range. The range from say 100hz to 1khz is much tighter, snappier and neutral(not fat and not thin) with the Genesis.

The genesis is rated for 4x100watts but prob puts out more like 130. The Audison is rated for 130w for the front ch's and 140 for the rears. On the Morels and the dyns both the audison and genesis sounded nicer than my pa500.4. Point to note here is that both the dyns and morels are rated at 200w rms. Both the dyns and morels have a lowish efficiency around 86-87 db hence they need around 130-140rms to really drive them. The Polk amp was prob falling short here with 90w per channel.

When I ran all three amps on the sr's, the diff between the amps was much less. Point to note here is that the sr's are rated at 125rms and have a higher efficiency at around 92db. Hence 90w per channel was enough.

To my mind once you cross a certain threshold (clean quiet amp that makes rated power) the question of which amp is directly related to " for which speaker".

In this case the sr's would be fine with the polk amp. Would I spend twice the money on amps to get the audison/genesis? Yes, If I was running morels/dyns, No if I was running the sr's.

Just my $0.02

arun1963

MacLeod wrote: »

This isnt a formula and I dont really know if there is one. Im sure there is but Im not smart enough to know it.

This is out of my Alpine 9855 owners manual.

http://www.fixya.com/support/p198869-alpine_cd_player_cda_9855_limited/manual-2090/page-21

Mac,

It's uncanny how almost everytime I jump to a new level, its becoz either I have finally understood the context of something you've said before or becoz you have given some additional info like the link above. PM sent.

MacLeod

Glad to have helped brother.

Thunderplains

Does THD play a factor in SQ?

cadenceclipse

iiii

cadenceclipse

how do u multiquote? hmmm

Thunderplains wrote: »

Does THD play a factor in SQ?

total harmonic distortion? i'd say so..

cadenceclipse

Thunderplains wrote: »

Does THD play a factor in SQ?

total harmonic distortion? i'd say so..

arun1963 wrote: »

If you're going to spend that kind of $$ on an amp (beyond a point, personally I would always spend extra on speakers rather than amps) then I would look at genesis amps over the audison. The profile ultra 4x100w rms beat the Audison LrX 4.1 in a pure a/b test I did while testing both Morels elates and the dyn esotec. Like all high end british amps, the profile ultra is very neutral with excellent speed, clarity and presentation across the mid bass/mid range. The range from say 100hz to 1khz is much tighter, snappier and neutral(not fat and not thin) with the Genesis.

The genesis is rated for 4x100watts but prob puts out more like 130. The Audison is rated for 130w for the front ch's and 140 for the rears. On the Morels and the dyns both the audison and genesis sounded nicer than my pa500.4. Point to note here is that both the dyns and morels are rated at 200w rms. Both the dyns and morels have a lowish efficiency around 86-87 db hence they need around 130-140rms to really drive them. The Polk amp was prob falling short here with 90w per channel.

When I ran all three amps on the sr's, the diff between the amps was much less. Point to note here is that the sr's are rated at 125rms and have a higher efficiency at around 92db. Hence 90w per channel was enough.

To my mind once you cross a certain threshold (clean quiet amp that makes rated power) the question of which amp is directly related to " for which speaker".

In this case the sr's would be fine with the polk amp. Would I spend twice the money on amps to get the audison/genesis? Yes, If I was running morels/dyns, No if I was running the sr's.

Just my $0.02

nicely put arun

cadenceclipse

pioneer premier a900. crutchfiled just scored a couple..

MacLeod

Thunderplains wrote: »

Does THD play a factor in SQ?

Not really. Its more or less an RPM for lack of a better word. It shows the level of distortion at a given wattage. For isntance, Amp A makes 50 watts at .04% THD, 70 watts at .4% and 100 watts at 1%. All its telling you is how hard youre having to push an amp to get that rated power.

For example, Amp A makes 50 watts at .04% THD and Amp B makes 50 watts at 1% THD, Amp A would be the more powerful.

That being said, those numbers are meaningless. ANY quality brand of amp will easily meet and most will exceed their rated power so judge the QUALITY brands of amps by their RMS rating.