Using Professional Amps On Home Theater Speakers

Are there any drawbacks other than fan noise to use pro amplifiers on hard to drive home theater speakers? I have several pair of the amp-killing 4 ohm Infinity Kappa 9 speakers that dip down to 1 ohm. To use six or eight of these speakers in a home theater would take a tremendous amount of money to power them sufficiently. There are certainly lots of speakers out there that are waay more efficient, but I already own these and would like to find a solution to power them sufficiently for my home theater. The Kappa 9 are about 85db efficient and suggest an amp of 60-340 wpc.

On the web I've seen a professional amp made by QVC, their MX2450 model is rated at 650 wpc @ 4 ohms and 1200 wpc @ 2 ohms for $750.

The amps will be 40 feet away from the seating area, so fan noise will not be a problem. Black background, liquid mids @ highs, wide and deep soundstage, "air", extended decays and all of the rest of the adjectives to describe a desirable two-channel amp is not important. I just want it loud and powerful. My home theater will be totally separate from my two-channel system.

Please weigh in with your opinions on this.

..thanks, Mitch
I've not listened to the Kappas and certainly don't know the real power or current they require to perform properly.

Also, I do understand you are just looking for HT sound, not top quality two channel performance.

Normally, I would not recommend a digital amp as I don't think they are very good with traditional driver speakers with regards to two-channel performance (I have never heard a Class D amp I was impressed with for this type of speaker and I have heard many and owned several). For the record, I think Class D amps are best on ribbon and planar speakers - but that's it.

But in your case, and since you don't seem to care that much about the quality, perhaps you need to lean in this direction. Though I have to warn you that my Bel Canto Ref. 1000s (1000 watts at 4 ohms per channel) were not powerful enough to properly drive my Thiel CS 6s while at the same time, my Mark Levinson 334 at 250 watts at 4 ohms did not have any problems in my sized room driving the same speakers.

What amps do other users of these speakers use to drive them? Are these speakers really designed to address that volume of space?

I know when my son DJs and he needs to cover a larger space/volume, he ends up having to use many subs (sometimes 6-8 total dual driver or sometimes quad driver sub/low bass units and is running thousands of watts just on the subs) just to properly pressurize the large room.

Why not go to Guitar Center and talk to the guys. You can rent a DJ rig for a weekend (excluding the speakers) or at least the necessary amps. Guitar Center lets their employees rent stuff privately, so you can probably get away for a few hundred dollars if you are just talking about the amps and the cables. It will give you an idea of what the sound will be like.
Ckoffend, I used Carver Silver 9t monoblocs (900 wpc @ 4 ohms) to power them. One pair of monoblocs did a good job, but with two pair of monoblocs in a biamp config, the speakers take a quantum leap and becomes a totally different speaker in a whole 'nother league. I had five pairs of those monoblocs and sold all of them, they were 20 years old. I suspected things may start to go wrong with them in the near future, so I sold them before they started to fail. The fees Carver charges to fix them was more trouble than it was worth. I also used the Sunfire Signature (1200 wpc @ 4 ohms) stereo amp to power them. I also needed two of those also to get the most out of the speakers...the Carver monoblocs were better than the Sunfire amps. I don't know what they were designed for, but one pair of bi-amped Kappa 9 can fill this room with ear-splitting sound without breaking a sweat with no distortion.

I had considered getting rid of the speakers too because they are so hard to drive.
I'd hate to see your power bill.

I don't dispute the quality of the performance of these speakers, as you seem to be quite enthralled by them.

Perhaps you could consider using these for your fronts and finding alternative speakers for your sides and rears. These alternate speakers are really more support based anyway and perhaps the Kappa's are being "wasted" on the intended purpose and location in some regards?

I got into HT for a while, ended up with 5 Wilson W/P 5.1s, but in the end, I didn't think the rear ones were really being put to good use - especially more so since I am not a movie guy.

Just a thought and it sounds like it may address some of you issues between amplification, speakers, and room fill. Part of me thinks that you are being forced into sub quality amps in keeping your speakers and based on the budget, and if this is the case, I suspect you will be disappointed after spending the money and not getting what you want.

Again, I would start by going to Guitar Center and renting the amps for a weekend, tell them how much power you need - if its 2000+ watts per channel, they'll have it. It will end up being the cheapest way for you to determine if you can go "pro level" amps.
I totally forgot about Carver. 7 old Carver cubes will blow your roof off-sound like crap but wow will it be loud!
I have an original QSC PLX 2402 that's used to power a Bag End 2-10" and an ELF 18". I did use it my two channel system for a few weeks. The PLX series has a switching power supply (not to be confused with class D) that is mechanically noisy for home use. QSC offers a wide range of amplifiers with different power supplies some of which are used in theater applications.

They are physically bullet proof. In the two channel system it lacked a very slight last little bit of finesse with a slightly closed in sound stage. On the other hand the bass weight would compare to the very best in the audiophile world.

Their low cost and customer service is outstanding. Used often in Bass amplification their representative is a fixture on the BassTalk forum.