Eminent Technology 8b Speakers - Amp/wattage Recommendations

bdp24 thanks for the reply. 

Your are correct, I built my own dipole subs. They are capable of playing up to 200Hz. So I think they will mate well with the 8bs. 

As for the amps, I would consider Music Reference but they are hard to come by. I will be in Sacramento next week and plan on taking a drive down to Quicksilver and having a listen of the KT mono amps. Should be interesting/fun. 

bdp24, my understanding is your are using the GR Research OB subs in place of the sealed subs on the 8bs. May I ask the details on how you are implementing the bi-amping.  Are you using a high pass filter of some kind between your main amp and the LFT mid and high freq panels? 

BTW, I called ET yesterday and mentioned adding dipole subs with the 8bs. They suggested running the dipole subs in parallel with the sealed subs on the 8bs. The supposed advantage is that with 4 subs in the room, room modes will be mitigated. Probably worth experimenting, but I am not sure it will be easy to get the sealed and dipole subs to integrate well together. 

Thanks decooney. Thanks for sharing your experiences. Agreed, a call to EMT will likely result in some clarity here. 

I once measured my existing system using a sound meter in a much smaller room. I was amazed at how loud 95dB actually is. I can't imaging playing any speakers lounder than that other than a brief moment. So my use of "fairly loud" was not meant to imply rock concert levels hur after hour. My most likely use will be in the high 80dB levels for an hour or two. 

Thanks for the LSA suggestion. 

I admittadly have limited experience with class D amps, GAN or otherwise. But one benefit of Class D is their lack of weight. A home demo can be arranged w/o incurring a fortune in shipping costs. 

In general I prefer tubes. Too me, they breath life into music. If GAN changes the equation, I don't know. 

Thanks all for the feedback. 

Just to be clear, the QS amps I am considering are the newer KT monoblocks which are rated at 100W with the KT 150 tubes.  I will discuss with both Mike Sanders and Bruce T at EMT if these will work. 

The 120 monoblocks are no longer available. 

Yes, the plan is to bi-amp using probably a QSC amp with DSP to drive a pair of dipole subs I built. 

The plan is to use:

1.  a HP filter between my preamp and the QS amp, which will driver only the mid and high frequency panels. I am not sure of the filter frequency just yet, but probably somewhere in the 50-100Hz range. If I'm not mistaken the mid panel driver plays down to 100Hz. 

2. Use the on-board Xover on the 8s to handle the crossover between the mid and high frequency drivers; and 

3. the built-in DSP/crossover functionality in the QSC to drive my subs. . 

With the above arrangement, I believe the low frequency drivers on the 8b's will be eliminated from the equation altogether.

I assume if the QS amps does not have to amplify the low frequencies, I am hoping to get more bang out of those 100 watts. This a fair assumption? 

Thanks everyone who posted and contributed to this thread. Very helpful and informative. Most of what I have heard is positive, and it would seem using the 100W QS will be a good match with the 8bs as I plan on using them. And yes atmashpere, I do plan on using a HP filter in front of the QS. I will contact Bruce T to discuss and confirm, but it seems like the QS monoblocks is the way to go for me.  

The Carver monos at $9500 is beyond what I wish to spend. 

Although I have not heard the Quicksilvers yet, I like everything else about them.  The utilitiarn look, no hype, no money wasted on marketing, a stellar name behind the brand, great customer service, and tons of positive reviews from real users. Cost is reasonable as well. 

I am glad I posted here on the forum. Many of the responses have removed my concerns. Thanks.  

bdp24 thanks for the pointers on the Rymthmik plate amp. My subs, although dipoles, are different. Maybe a dozen years ago, there was a speaker company called Surreal Sound that made a speaker called Fifth Row. They never made it commercially. A few months back I managed to purchase on the cheap the modules needed to build their subs from the designer. Here is a link that shows the subs. The plan is to drive the subs with a QSC amp and the 8bs with probably the Quicksilvers. 

No worries at all ledoux1238 about discussing the 8c woofer upgrade in the context of this thread.

Unfortunately in my case, the 8c woofer upgrade was released by ET well after I invested money and a whole lot of labor into building my subs. So the 8c upgrade is a bit late for me. That said, if the 8bs have a weak link, it was the bass. I can only assume Bruce has addressed this issue with the 8c upgrade.   

There are many ways to integrate your subs.  None of them, however are ideal. 

I am not a fan of using a L & R of mini DSP units as active cross overs between the subs and the mid LFTs. As you indicate, that requires A/D and D/A conversions. 

I will probably do a mix of analog and digital. My preamp has RCA and balanced outputs. The RCA outs will be fed through an analog HP filter and then to my main amp. The balanced outputs will go to a QSC amp with DSP and LP filter. A plate amp can be used as well. Although I have not tried it yet, my understanding is the A/D and D/A conversions really do not matter at the lower frequencies. 

I will probably call Bruce T tomorrow.  Besides discussing amps, I would like to learn more on how he implements the 8c subs, crossover frequencies, etc. 

Now that the 8c is available, I would be inclined to use Bruce's solution over the GR Research subs, assuming you can bi-amp and avoid the A/D and D/A conversions for the mid and high LFT drivers. 

ledoux1238 can you talk a bit more about your experiences of using a 20 watt amp with the 8bs?

Are you bi-amping. Is the Mactone driving only the mid & high LFTs or also the sub drivers as well? 

Are you hearing any noise or distortion of the amp at 95 dB?

Are their any compromises in your view of using a lower watt amp with these speakers?

Do the 100 watt amps do some things better? 

Here is a link to the ET website describing the 8c update. For $1500, it is probably well worth it. 

http://www.eminent-tech.com/LFT-8cwooferupdate.html