Big amp produces average sound? Smaller amps had bigger bass ... 20000 watts packed up in one room....


Bronze Member
Username: Invictuz

Seattle, Wa Usa

Post Number: 22
Registered: Jan-05
Question / Request for comment:
Do you have experience with big amps? What are ideal settings for sealed 10" subs @ 1 ohm?
Should a 2500d pushing four 10" DVCs @ 1ohm be able to surpass the performance of four Rockford Fosgate (RF) 301ms pushing the same subs at 2 ohms in a one amp/one sub configuration?

Some of you may remember me from a month ago asking questions regarding the pros and cons of multiple identical amps pushing multiple identical subs in a one for one configuration (four RF 301ms and four MTX DVC 81044a).

Here's my thoughts on the subject after swapping my four 300w RMS mono blocks for a 2500d...

After two weeks of listening I find myself disappointed in the performance of the 2500d. Don't get me can hit moderately hard its just not mind-blowing output.

I do not feel the same impact in hard bass drops.
There is a "weakness" in the Orion when compared to the RF 301m pushing the same speakers...barely noticeable but there is definitely something missing.

The power draw is only slightly less noticeable.

Quick Comparison between RF 301ms and Orion 2500d:
Dampening factor of RFs = >200
Dampening factor of Orion = >50
THD of RFs = .05%
THD of Orion = .9%
Signal to Noise, RF = >100db
Signal to Noise, Orion = >80db

Maybe I have something set wrong on xover of the amp...I am spending this weekend measuring output and adding another ground to my battery...

after careful review and many questions I went with a larger amp and yanked my 301m's.
I choose an Orion 2500d (couldn't find any HCCA, USAmp or Zapco that would deliver 1200+ watts when I was ready to buy...though have seen many since...damn impatience).

Current configuration:
Jeep Grand Cherokee limited
Alpine 9833

1 MTX 301x
1 JVC 4750
1 Orion 2500d
4 RF .5 farad caps

1 Pair Infinity 6000CS (front doors)
1 Pair Infinity 62.3 (rear doors)
1 Pair Infinity 1001t tweeters in dash
4 MTX DVC T81044a 10" subs in sealed enclosure

0 gauge front to rear distribution block "A"
4 gauge from block "A" to each cap
4 gauge from + to + on two Caps making pair 1
4 gauge from + to + on two Caps making pair 2
4 gauge from pair "1" + to Orion input 1 +
4 gauge from pair "2" + to Orion input 2 +
4 gauge grounds for caps
4 gauge grounds for Orion 2500d

4 gauge from block "A" side to block "B"
8 gauge from block "b" to JVC (rear channel)
8 gauge from block "b" to MTX (front channel)
8 gauge ground for JVC
8 gauge ground for MTX

Subs wired for 1ohm (actually load is 1.2Ohms)

From my previous install I have removed four 301m amps, 1 pair Infinity 6000cs (swapped for 62.3s), 1 JVC 4750 amp.
I swapped most wire for 0 or 4 gauge.

Bronze Member
Username: Invictuz

Seattle, Wa Usa

Post Number: 23
Registered: Jan-05
Here is a quick snapshot of what was and now is...

four Rockford Fosgate 301m amps pushing four MTX 81044 DVC 10" subs...

To ensure its done right i started from the beginning and removed everything

now the Orion 2500d is in...

Silver Member
Username: Joe718

Brooklyn, NY

Post Number: 332
Registered: May-04
are your subs dvc 4ohm or 2 ohm? if they are dvc 4 ohm you can only go down to a 2 ohm load, at 2 ohms that amp only produces 1700. If your subs are dvc 2ohm then you should be straight you would get the whole 2500. If thats the case check out your gains and your crossover maybe you have it set to low. Try tuning it to about 80hz Also that amp requires alot of current, if you havent changed your alternator, its not going to get the current it needs. Good luck

Gold Member
Username: Carguy

Post Number: 1881
Registered: Nov-04
Invictuz, I think you got used to class AB's sound quality. There are people that will argue that class D amp will reproduce same bass quality as AB, but from my numerous testing and experience, AB always showed better results.
I know exactly what you mean by "weakness". Class D amps seem to require more careful setting than AB. It can give somewhat pleasing result, but don't expect the same "punch".
I think you would've been much happier with Orion's HCCA 275G4/Xtr 1400, PPI's Art series 1200.2, Zapco's C2K 6 (it's on sale on eBay for $400 right now).
The best way to describe/explain is to get class D 1200w rms amp, and class AB 1200w rms and test it side by side.
In spec wise, they both should produce "same" sound quality/punch, but somehow, it didn't for me.

Bronze Member
Username: Invictuz

Seattle, Wa Usa

Post Number: 28
Registered: Jan-05
Thanks for the reply.
i have the subs wired to present a 1 ohm load.

i will tune to 80hz and see if that works.

i have four .5 Farad caps wired in two pair feeding the 2500d pair of power inputs.
i have upgraded the stock alternator from 90amp to 125amp (though considering upping it further)
i have a larger than stock battery (biggest on Schucks sold, required some effort to get it in)

Unregistered guest
125 amp? WOW...I have 2 type X 12's in my car with the 2500D...My stock 110 amp altenator was out of the question...i run a denso 180Amp with 2 farad caps and an upgraded battery, and i still have issues with power surges with heavy bass on the 2500D. no doubt in my mind you are lacking power.
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