Tempest Questions

[karl k]

You might be right about the amp lacking in some fasion. I won't tell you it's the lack of power(although it may indeed help) as it could also be a lack of damping ability of the amp. I can't tell you what the damping factor of the amp is but I'm pretty sure it's nothing to brag about. You might consider using a pro-sound amp instead of a plate. Maybe a Crown, Carver, Mackie, Numark, ect. will have enough of a damping factor to prevent the loss of control. I've driven my plate(same as yours) pretty hard and only had probs with peaks at or above 250wts. You may also have these probs if you have bass boost dialed in on the receiver via DSP's, Bass/tone adj, Active Eq/Speaker Eq settings or the plate itself. Check with PE on the boost option for that amp and see if had it or not. Look in the ext. specs on the web for identifying resistor values for location and degree of boost if at all. I've had alot of amps clip and drivers bottom due to this.

Over all, sounds like a well planned and executed project. Ya gotta luv it when a plan comes together!

[grampi]

The PE amp I have doesn't have the bass boost. I sent PE's technical dept. an email asking them if they could tell me what the dampening factor of this amp is. Where is a good place to look online for the amps you mentioned? Which one is likely to provide the best quality bang for the buck?

[grampi]

After doing some quick searches, I'm finding these amps are quite a bit more expensive than the plate amps, but they also have much better specs. I guess you get what you pay for. The only thing I don't like about these amps is the fact they're located in the entertainment rack with the other HT equipment, which means having to run long sections of large gauge speaker wire to the sub. This wire also is very expensive. That's what's so nice about the plate amps. They're directly mounted to the sub, eliminating the need to run long, expensive amounts of speaker wire. Doesn't anybody make high quality plate amps?

[Dave Bullet]

jbandpc,

I did what MCH did for my Shiva. (I believe they both have the same "rim / flange" height). I jigsaw'ed another 3/4" MDF piece to flushmount my Shiva by laminating it to the baffle. (My baffle was already 1.5" thick and braced :-) Now it is a real dead weight :-)

I wouldn't rip off any cardboard. Besides, if you want to put a metal grille over the driver for protection (as I did), the cardboard on the driver allows you to mount the grille without rattles.

Dave.

[karl k]

Good luck with your request from PE...

I asked them about the damping factor and the slew rate and got nothing. They explained that it didn't matter and that was the end of my search for that info. For the money, my guess would be a DF of about 30 or 40 but we'll never know. The examples of amps I sited may be a little pricey but there are some others I couldn't think of their names of the top of my head. Some more moderately priced(in the $200-$300 range) are American DJ, Gemini, Pyle, and Samson. As you said, you mostly get what you pay for. As I was told by an old friend(remember Steve W) these amps are built for commercial use and will take quite alot of punishment ie. last a long time. Look for something in a DF of 100 or more and a SN ratio of 95db or better as well as mono(bridge) capability and you'll do alright. Search for Pro Sound and there's alot of retailers out there.

I agree about the convenience of plates as well as the bang for the buck, but don't believe you have to mount the "DJ amp" in the rack. Yopu can conceil it just about anywhere in the room and run your long cables as low level RCA for less cost. Besides, when you start talking about that 500wt or the 1000wt amp from PE, you're talking about the same or more money as with the others.

Just something to think about.

[grampi]

It's been my experience that amps with a DF of 200 or more sound the best. If the PE amps are only 30 or 40, that's horrible! I've heard amps that had a DF of between 100-200 that didn't sound good to me.

The Mackie 1400i looks pretty decent. There's a couple of them on ebay for a not too bad price. I'd have to run it in stereo as it makes way too much power for one Tempest in bridged mono (well in excess of 1000 watts). It puts out 250 X 2 in stereo into 8 ohms. I think its DF is over 300. I will also look at some of the others you mentioned and see what's out there.

[grampi]

Here's what I've found out so far. Because the Tempest is a DVC driver with each coil being 8 ohms, I need an amp that'll push at least 250-300 watts into 8 ohms in stereo, or 500-600 watts into 4 ohms bridged mono. The only 2 I've found that will push this kind of power into these loads is the Mackie M1400i, and the Crown XLS 402. Both have very good specs with S/N ratios of >100, and DF >200. They're a bit pricey if purchased through retailers, but seem pretty reasonable on ebay. The M1400i seems really nice. It pushes 1400 watts into 4 ohms brideged, which would be nice if I ever wanted to run 2 Tempests with it.

[karl k]

I shopped for a new HT receiver last year and of those that I could confirm the DF on,(in my price range of $500-$600) the Yammi was the highest at 80. The others were down around 30-40. Mind you, it's not a common spec to put on the sheet, so there wasn't much info to go on for comparison. I had an old Carver "car" amp years ago and it had a DF of 100 and really did a good job with control. Most pro sound amps I found above the $250-$300 range were at least 100 as you've found yourself. Any would certainly be better than most of the plates offered today(for the money).IMO

If it were me, and if I remember correctly, the Mackie M800 would be a prime choice for my use on a sub. Another would be the Numark Dimension 3. Both were bridgable to somewhere around 600wts at 4ohm and both were in the $350-$450 range not to long ago. You may have to search and wait for a sale, but it does happen.

Here's some links I saved in my search's...

http://store.yahoo.com/efunctional/dimension-3.html

http://www.audiolines.com/ (goto audio menu, amplifiers)

http://www.musiciansfriend.com/srs7/.../search/c=4600

http://www.abemusic.com/samson/f1200.asp

Now, these were only the ones I saved due to either pricing, or info about the product. To find further info, you may have to search for the manuf. web sites as I don't have them myself to give. My only point here is to keep an open mind, do a little shopping before you make your decission, and BUY FOR THE FUTURE!!! There's times I regret not going with the prosound stuff to maybe gain performance(or maybe not) but the funds just weren't there at the time and I was on a schedule to get done before the wife left me for the mess I created!!!

Foot note...

Even if the rated power output is in excess of your needs, you can still turn the gain down on some amps or your source receiver/preamp and be safe.Ultimately, you will not use most of that power... most of the time unless you have the mains to back it up with.

[grampi]

So what's the deal with the poorly built plate amps? Doesn't anyone build any quality ones? That would be the way to go, if only someone made a decent one.