How much power does a Larger sub need?

ctviggen · « **Reply #40 on:** 13 Jan 2005, 09:05 pm »

That is true. I just just thinking it would be fun to play around with the Eq to see what happens. In the end, I'll likely get a TACT, but the TACT is a lot more than a simple Eq. For right now, I'm just looking at options, and don't want to spend the money for a while, if possible. I need to do the putty adjustment on the Larger and see what happens.

ctviggen · « **Reply #41 on:** 13 Jan 2005, 09:10 pm »

I should've said "a lot more money" than a simple Eq (and, granted, a lot more functionality, too).

doug s. · « **Reply #42 on:** 13 Jan 2005, 09:47 pm »

bob, for the money, you could pick up a used qsc amp and a used eq (like behringer, dbx, etc), for not much more than a pair of those plate amps, if that much. then, when yure ready to move up to a tact or sopmething similar, you will still have left a killer sub amp!

doug s.

ctviggen · « **Reply #43 on:** 13 Jan 2005, 10:21 pm »

I wasn't thinking about that -- two plate amps would be about $800, and a used QSC wouldn't be too much more than that and could drive two subs (or really, really drive one). Good idea!

doug s. · « **Reply #44 on:** 13 Jan 2005, 11:12 pm »

Quote from: ctviggen

I wasn't thinking about that -- two plate amps would be about $800, and a used QSC wouldn't be too much more than that and could drive two subs (or really, really drive one). Good idea!

the particular amp that i posted f/a will not even make it to $800, & it's really quite the monster amp; smaller ones, still more than adequate for vmps subs, imo, will certainly sell for less. here's another 3002 for "buy-it-now" of $620:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=23787&item=3775723824&rd=1
lots of these on ebay, a search for "qsc plx" comes up w/these:
http://search-desc.ebay.com/qsc-plx_W0QQsofocusZbsQQsbrftogZ1QQcatrefZC6QQsojsZ1QQfromZR10QQcatrefZC6QQftsZ2QQftrtZ1QQftrvZ1QQsadisZ200QQfposZ20892QQfsopZ1QQfsooZ1QQcoactionZcompareQQcopagenumZ1QQcoentrypageZsearch
even the mondo plx 3402 usually goes for <$800; see completed auctions:
http://search-completed.ebay.com/qsc-plx_W0QQcoactionZcompareQQcoentrypageZsearchQQcopagenumZ1QQfisZ2QQfposZ20892QQfromZR10QQfsooZ1QQfsopZ1QQftrtZ1QQftrvZ1QQftsZ2QQsadisZ200QQsbrftogZ1QQsofocusZsoQQsojsZ1

even the "baby" qsc plx 1202 makes 200wpc-8ohms/325wpc-4ohms... if i dint awreddy have a nice pair of electrocompaniet amps to use for sub amps, i'd go w/the qsc's...

but, i am not sure i'd bridge 'em; for a pair of the larger subs, i'd run a pair of stereo amps, w/each amps' channel driving a separate woofer. usually (but not always), running an amp non-bridged will give better sonics than bridging. i had a pair of original-iteration adcom gfa555's that were relegated to subwoofer duty before i replaced them w/the ec amps. even w/only one channel of each amp driving each of the larger subs, (before i got a second set of binding posts to use both amps' channels), the subs sounded better than when i ran them in bridged mono...

regards,

doug s.

brj · « **Reply #45 on:** 14 Jan 2005, 12:45 am »

I'm not that familiar with these amps, but isn't it something of a concern that they don't double their power from 8 Ohms to 4 Ohms when considering them for sub duty? Subwoofers tend to be current hungry, and I was under the impression that the "doubling" characteristic was one of the prime indicators of a high current amp.

I didn't really notice the specs before, and Brian's recommendation goes a long way, so I was curious about the apparent dichotomy.

Thanks!

doug s. · « **Reply #46 on:** 14 Jan 2005, 08:01 pm »

Quote from: brj

I'm not that familiar with these amps, but isn't it something of a concern that they don't double their power from 8 Ohms to 4 Ohms when considering them for sub duty? Subwoofers tend to be current hungry, and I was under the impression that the "doubling" characteristic was one of the prime indicators of a high current amp.

I didn't really notice the specs before, and Brian's recommendation goes a long way, so I was curious about the apparent dichotomy.

Thanks!

specs can be misleading - sometimes mfr's will intentionally "under-rate" the power at 8 ohms, so they can say the power doubles.

in any ewent, in this case, the power increase as ohms drop is still adequate, imo, & they are stable to at least 2 ohms. this, combined w/a damping factor >500 seems to indicate these spec extremely well for subwoofwer amps.

doug s.

ctviggen · « **Reply #47 on:** 14 Jan 2005, 08:06 pm »

I noticed that the winner of one of the auctions was a jgubman. Isn't there a jgubman on this site, too?

doug s. · « **Reply #48 on:** 14 Jan 2005, 08:09 pm »

Quote from: ctviggen

I noticed that the winner of one of the auctions was a jgubman. Isn't there a jgubman on this site, too?

a search of his name comes up w/181 matches...

doug s.

jgubman · « **Reply #49 on:** 14 Jan 2005, 08:32 pm »

You caught me, I grabbed the "Buy It Now" 3002 for $650 shipped yesterday. Works out to be less expensive than buying 2 of the 1000W plate amps.

Will be powering a pair of Megawoofed Largers with the 3002, I'll let you know how it works out.

BTW, this subwoofer change will be replacing a pair of SVS 25-39CS subwoofers powered by a 150w x 2 Fidek amp. I'm expecting a big improvement.

ctviggen · « **Reply #50 on:** 14 Jan 2005, 09:01 pm »

Aha! Nabbed 'ya! Let me know how that turns out. I have one Larger and one SVS 25-39 (powered by its internal amp). I want to get another Larger and then either keep the SVS for another corner (for movies) or sell it.

zybar · « **Reply #51 on:** 14 Jan 2005, 09:16 pm »

Quote from: ctviggen

Aha! Nabbed 'ya! Let me know how that turns out. I have one Larger and one SVS 25-39 (powered by its internal amp). I want to get another Larger and then either keep the SVS for another corner (for movies) or sell it.

Bob,

I have an excellent condition PLX3402 that I will sell for only a little more than it's baby brother that was just bought.

If anybody is interested, you can read my original post here:

http://www.audiocircle.com/index.php?topic=10776&highlight=

George

jgubman · « **Reply #52 on:** 14 Jan 2005, 09:27 pm »

Damn you zybar, I actually was reading that post yesterday as I was quickly doing some last minute research on the QSC...

I figured there was no way you still had that amp, otherwise I would've bought yours in a heartbeat...

damn

brj · « **Reply #53 on:** 14 Jan 2005, 09:35 pm »

George, did you ever get around to the comparison with the K2?

zybar · « **Reply #54 on:** 14 Jan 2005, 09:38 pm »

Quote from: brj

George, did you ever get around to the comparison with the K2?

Sorry to say I didn't and I probably won't have time to...just not enough hours in the day.

George

jgubman · « **Reply #55 on:** 15 Jan 2005, 03:22 am »

So how are you guys hooking up your sources to these pro amps?

I currently have a RCA cable going to a RCA -> 2 RCA y-cable going to two RCA -> 1/4" Phono plug adaptors -> amp.

Does a more elegant solution exist? Is there such a thing as a Female RCA -> 2 1/4" phono plug y-cable? How about Female RCA -> 2 XLR y-cable? I'm guessing a RCA -> XLR wouldn't be optimal for gain reasons...

grub · « **Reply #56 on:** 16 Jan 2005, 12:09 am »

I have a QSC RMX 2450 I recently purchased to power my sub (wich will be replaced with a Larger sub sometime in the future).

It's heavy, has loads of power, and an annoyingly loud fan. I'm looking into the fan problem and I may have found a solution.

Thankfully, QSC uses a fairly standard 80mmx80mm fan (like the ones inside a computer), but they run a 24Volt fan instead of 12. I've ordered a quiet fan from an online computer store, and I'm planning on cutting the voltage with a 12v regulator.

I'll report back with results.
-->grub

ctviggen · « **Reply #57 on:** 17 Jan 2005, 06:13 pm »

I was going to do RCA to XLR, if I can have a cable made. The QSC website has a user's manual that shows how to make the connection for the XLR in unbalanced mode:

http://www.qscaudio.com/products/amps/plx/plx.htm

jgubman · « **Reply #58 on:** 12 Feb 2005, 09:31 pm »

Well, I finally got the PLX 3002 (eBay shipping nightmare...) and hooked it up last night.

I was using a Fidek FPA-3002 (300W x 2) and the QSC seems to have a little more authority.

However, the fan noise is killing me. I can't live with it.

Has anyone used the QSC w/ the fan unplugged? The Fidek had a similar fan noise, and the fan was removed a few years ago and the amp has been fine. I wonder if there'd be a problem doing the same to the QSC, otherwise, I'll have to hunt around for a K2...

zybar · « **Reply #59 on:** 12 Feb 2005, 09:50 pm »

Quote from: jgubman

Well, I finally got the PLX 3002 (eBay shipping nightmare...) and hooked it up last night.

I was using a Fidek FPA-3002 (300W x 2) and the QSC seems to have a little more authority.

However, the fan noise is killing me. I can't live with it.

Has anyone used the QSC w/ the fan unplugged? The Fidek had a similar fan noise, and the fan was removed a few years ago and the amp has been fine. I wonder if there'd be a problem doing the same to the QSC, otherwise, I'll have to hunt around for a K2...

If you need a K2, shoot me a PM.

George