Originally Posted by dstew100
Can these 4 ohm high sensitivity speakers be driven with a standard AVR such as the Onkyo 818 (which has 8 and 6 ohm RMS specs but has a 4ohm dynamic power spec)?
Absolutely. The speakers are very senstive - and crossed over to the subs high, so a typical middle tier AVR like the 818 is perfectly adequate for driving these speakers --- (much more so than the typical low sensitivity speakers driven by most). As to how much difference in sound an amp makes - I don't think it makes much of any difference at all until you exceed the limits of the AVR - which with a set of high efficiency speakers like these and a mid tier AVR is typically quite capable of producing reference level playback in room - especially if fewer channels (rather that all channels) are driven. IE - AVR's typically have a shared power supply for the amp channels meaning that as you add more channels to power, your available wattage for each channels is dropped as compared to a standalone amp where the power is dedicated to each channel.
Here are some measurements I took comparing two of my pro amps and my Onkyo TX-NR1007 AVR.
Originally Posted by GIEGAR
Hello fellas, I've been silently following the official JTR speaker thread for over a year but the buzz around the 228HT has me breaking cover!
I'm very interested in these, especially the at intro price. The 228HT look like an outstanding high-performance audio bargain to me. Thanks all for the great impressions so far, especially Archaea for all his enthusiastic work.
I expect I'll have a few questions to help me feel "warm & fuzzy" about what will have to be a no-listen purchase. Here's one from a while back for now:
Originally Posted by Archaea
I ran Audyssey last night on the 228ht and I am happy to report Jeff's stated 70Hz crossover point is exactly what was assigned by audyssey. In the exact same position the eD cinema 12 always were registered as 120Hz or 150Hz crossover points.
Archaea, I recall from somewhere that you are driving these with an Onkyo TX-NR1007. Could you let me know the values Audyssey reported/set your level trims and distances at for the 228HT's? I also have the '1007 and would hate to run into level trim problems due (in part) to the high sensitivity. (My speaker > MLP distance is 3.75m/12.5ft.) I realise that this will not be definitive, but will be a fair sort of indication for me. Thanks a lot.
More questions for the JTR gurus tomorrow... Have a great day!
Thank you for the feedback. Yes you are correct, I do have a TX-NR1007 AVR.
I've found these speakers to be noticeably less sensitive than the Noesis 212HT and eD Cinema 12, but still quite sensitive in their own right. The Noesis 212HT always registered at -12 in my room on Audyssey, meaning they were more sensitive than my room was really setup to use on the Onkyo TX-NR1007. Audyssey was calibrating them at the minimum trims and they were still exceeding the 75dB rating at my main listening position. Which is a fear you alluded to. The eD Cinema 12 were very similar. My trims on the eD Cinema 12's were always -11.5 or -12. IIRC the traditional JTR Triple Eight's I had in my room for a time that belonged to bluesprings1 might be a bit more sensitive than the JTR Noesis 228HT based on my experience, even though they are both (triple eight and 228HT) rated at 98dB/1watt.
My trims on the Noesis 228 HT are -7.5 dB for left channel and -9 dB for right channel on my Onkyo TX-NR10007 at distance settings of 11 feet and 10 feet respectively to my main listening position. I don't sit dead center. I sit to the right in the third of four chairs. You can see my room in my pictures in this thread or my signature pictures. The distances are accurate and I've verified with the SPL meter of the omnimic that these spl levels are right after Audyssey set them. They match spot on to the 75dB expectation with real measurements of 74.8 - 75.1 in my room at the MLP.
The crossover was detected at 70hz by Audyssey and my omnimic confirms that is accurate in full range sweeps, they fall off pretty hard at that point, regardless of placement, but that is by Jeff's design. Mine are out about a foot from the wall currently and stil register as 70hz speakers in Audyssey. I bumped them up to 80hz, and think I like 100hz crossover better for music with the captivators in early impressions. The eD's I liked best with about a 150hz crossover for music for comparison. My Wharfedales, I liked an 80hz crossover.
One thing to note.
I am increasingly starting to think my surrounds should probably be upgraded at some point. I have Klipsch surrounds, and Wharfedale sapphire SP-87 towers hung on the rear wall for the surround rears. Neither is capable of keeping up with the dynamics of the JTR. In fact in my recent demo with some visitors I was asked if I ran my surrounds at lower levels by preference. I chuckled and said no - everything is level matched and double checked. The Klipsch and Wharfedales keep up fine at lower levels - say -10 or -12, but when I turn it up to reference levels for demo sessions the surrounds basically get lost in the mix because they can't keep up with the dynamics of the front soundstage.Edited by Archaea - 3/12/13 at 8:38pm