I'm still in the middle of getting my system completely tuned and kick a**. So far it sounds great but I'm looking for a little more quality sound during the higher volumes. Please bear with me as I describe my system so you have enough information to give an educated response.

System so far in a 2002 Land Rover Discovery
- Empeg
- Diamond Audio Hex 600s Components
- Diamond Audio m361i Coaxials
- Diamond Audio D7054 (50Wx4) Amp
- CDT MS-80 8" Sub in custom fiberglass enclosure

The components and the coxials are run from channels 1 & 2 of the amp. The sub is bridged on channels 3 & 4. The first thing I did to improve the sound was to switch the sub (originally a Diamond Audio 8") to a bazooka sub. This helped a lot in the low end but was distorting during high volumes. Next I upgraded the sub again to a CDT M80 which has been reviewed as the best 8" sub available. Now the bass really kicks (most people would think they were listening to a 12"). Finally I spent about 6 hours tuning the system via the built in active crossovers on the amp (the DA Amps house some of the best crossovers available on the market). (Little fact - Diamond Audio used to be called Esoteric). Anyway.. I now have my system tuned great with all EQ, Loudness, BASS and Treble settings at zero. I'm able to achieve a high volume before any distortion but I want a little more (mainly in the midbass and very low bass fequencies).

Would adding a 2nd AMP help? From my understanding, the more power (within reason) you have available on the system, the less the amps have to work and overall get better imaging throughout the spectrum. My analogy is with lifting weights. A weak person works much harder to lift the same amount of weight that a very strong person lifts. And the strong person does it more finess and has more enegery left over to do it again.

My idea is to add a second 2 channel Diamond Audio Amp and bridge the 2 channels to run the sub (approx 300W @ 4ohm). Then I would use the original amp to run the components on channels 1 & 2 and the rear coaxials on channels 3 & 4. This will also give me the oppurtunity to use the crossovers seperately on the components vs. the coaxials.

So.. Would the 2nd amp give my system more leverage and flexiblity to produce quality sound at a higher volume?

Thanks for reading and look forward to the replies.

Rob

This, from a guy who had the best sounding system I'd ever heard.

One thing I'm discovering about MY system is that "distortion at loud volumes" is a very EQ-dependent thing. Before I ran through my RTA passes, I'd EQ'd everything by ear, and the system was able to get quite loud without distortion, although I wasn't totally happy with the sound. Now, I can't get it as loud before getting distortion on certain material, but it sounds much better.

My next goal is to find exactly which frequencies are distorting and see if I can notch-correct those in the equalizer.

It's possible that on your system, you could do a similar thing. Find out what frequency is causing your loud-volume distortion, and notch it a bit with a very high Q. Remember that beta 11 has a bug with the Q where it only works on one channel if you adjust it in locked LR mode, so you have to adjust L/R separately if messing with the Q.

I don't have anything constructive to add, but I'd be interested in listening to your system when its all said and done.

If you want, I can come by sometime and help you tune your EQ. I'll try to discover wacky-ass values that look like nonsense, yet sounds pretty good.

Calvin

I am basically doing the same thing with my four channel amp. Running front and rears off the front channel of the amp. Doing this does increase the THD of the amp due to the lower ohm value the amp sees. Not sure about the spec of Diamond THD at different ohms but its worth checking. Of course the only fix to this would be to do what you said and get another amp.

i have a question... whats that baffle thing that you have for your sub? is it to just reflect the soundwave back towards the front of the car, instead of using the trunk's walls?

Yeah, like I said in the caption for the meet photo, I'm very interested in the details of that baffle thing, too.

I don't know much about amps, what I have learned I have learned from tanstaafl. I have a a/d/s P850 which has 8 channels. 1&2 run my dash speakers, 3&4 run the doors, 5&6 run the rears and 7&8 run my one 10" sub. I like being able to tweak each set of speakers individually. I'm not sure about the power question but you would have more tweaking options running the subs off their own amp. I have the Diamond S400S in my dash and they are incredible on the highs. So your car must sound pretty damn good.

It will definitely help. Even the competition systems in the low power ranges run such low impedances that the effective output is very high.

You could run the subs, and the rear speakers only off the amp and get another for the front. Or, run all 4 speakers from each channel of that amp and get a new one for the sub itself. Or, my favorite - get a 5 or 6 channel amp that does it all under one shell.

Historically, rear speakers need about half the power of front speakers, and a sub about double the power of the front speakers. It's a good ratio to begin with anyway.

I think not only the increased power, but also getting the sub onto it's own gig would help as well. A 5 channel amp should already be set up that way though... I particularly like the Alpine MRV-F450. I've convinced mafisto to get one for his car.

EQ is not the problem. A perfect system will have near 0 levels on all EQ settings. Minute changes on an EQ can have drastic changes for different songs/genres. With a clean amp, power headroom, and amazing components (with matched crossovers) you should have your system tuned with little adjustments from the EQ (focus on the active crossovers). I have tuned my system using an ocilliscope so I have my gains and the EQ near perfect before getting any clipping (and everything is at near zero now - the highest EQ setting is at +2db). However I do believe I need more power in the system to maintain the clean signal.

I have decided to go with the 2nd amp (another Diamond Audio) and I'm scrapping the 8" sub and having a new 10" fiberglass sub enclosure made (with probably a CDT or Eclipse 10" sub). The fronts will run from the 4 channel amp bridged to 200W a channel at 4 ohm. The rear speakers will run from the RAF (rear audio fill) outputs of the component crossovers. The sub will then run from the new 2 channel sub bridged to 600W at 4 ohm. I think this would give me all the headroom I need.

The baffle thing in my current sub helps keep the sub nice and tight and lowers the amount of resanance I get from the plastic rear quarter panel (basically displacing the sound and making a more ambient boom). With the new 10" enclosure I'm going to sound proof the entire rear quarter panel.

I've gone this far with the system so I'm not stopping until I'm REALLY happy.

In reply to:

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The baffle thing in my current sub helps keep the sub nice and tight and lowers the amount of resanance I get from the plastic rear quarter panel (basically displacing the sound and making a more ambient boom). With the new 10" enclosure I'm going to sound proof the entire rear quarter panel.

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where would i purchase one of those? i have a 12" cylindrical enclosure so it fires towards the rear like yours.

Mine was custom made by the same installers (Monney Car Audio - Redwood City) that made the sub enclosure.

www.monney.com

Presumably the vehicle can supply enough electrical current to handle the peak demands of, say, some heavy Bach organ music piping out to all of those amps? Big battery, bigger alternator?

Cheers

Oh yeah... Anything fairly new (ie 2002 Land Rover) should be good enough to handle the load. Also, anything with a good size alternator (ie 2002 Land Rover) will be able to handle it.

Only when you try stuffing a dozen amplifiers into a Ford Escort do you need to worry about power handling. BUt an amp or two in this guy's ride won't have any problems.

All statements above are assuming that things are hooked up "correctly" though... To me, that means running an 8 or 4 gage wire from the battery back to the amps, a proper power distribution block, and a good size fuse right at the battery for that wire itself. Ground wires should also be of decent size, and grounded to the nearest convenient chunk of metal with a star washer underneath for good contact.

But yeah, the battery and alternator will be fine, I'm positive of it.

I tend to agree with you up to a point. The cabin layout can drastically alter the sound, so while I have pretty good to excellent components, having no roof really changes the sound quite a bit.

Calvin

not entirely correct, the current amp I'm running will KILL 9/10 electrical systems in just about every car. I have a earthquake phd2 and it rms's 2000 watts even w/ a couple caps and a couple 2v gell cells it make my car upset.