Speaking of measurements, azryan, what's the spec's look like on your eAR amp?

Azryan (and others) might find this link interesting: charlie's speakers (including his in-wall subs).

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

DROOL!!!!
Nice work Charlie, looks great!

Holy cow!!

Very slick looking that's for sure, but those speakers (esp. the mains) are Tremendously far apart. What is that like 20' apart by the looks of it??

That center speaker is the misused 'gap filler' I spoke about near the end of the 'infamous' SPL meter thread when Matthew asked me about my 'phantom center'.

In-wall speakers regardless of distance have thier own inherent flaws being coupled to the walls and having massive baffle problems, and or course no chance to reposition them for anywhere near optimal use (which they ain't at now).

I wouldn't worry about a digital amp Charlie, and I understand now why most amps sound the same to you.
If you're so interested in (hung up on IMO) measurements, you might wanna measure the freq. response of those speakers for a eye-opener.
Soundstage depth, imaging, solid surroundfield. None of which are possible here.

Crap, I hate to sound so rude again, but wow, for someone talking hi-fi amps and thousands of $$$'s in measurement equip. to not know this stuff is pretty wild.

The room does look very very nice though Charlie. And you certainly don't have any speakers in anybody's way. I guess that could be a plus?

I ment the 'peter out' comment as a joke, but I'd just used a and didn't want to come off as a grinning idiot. A straight faced idiot, OK, fine

There are obvious early reflection and diffraction issues I need to deal with ASAP, but I really intended this to be more of a HT than a music system. I also had to work within tight space and WAF constraints. For HT it works pretty well. Preliminary measurements indicate pretty good response - I'm waiting on delivery of better test equipment to get better measurements, but remember - I can tune the crossover to fix quite a lot as this is totally custom work.

I want to build a set of Dynaudio (got the parts) speakers for music and locate that system elsewhere. After that I'm thinking about a pair of Bohlender Graebner based monopole ribbons.

Or, if things continue I may be relocated and get to do Charlie's HT v2.0....

No x-over adjustments will fix the drastically too far apart distance of your mains. For future ref. in a v2.0 HT design I'd work on altering that.

You said the freq. response is pretty good? Is this from 1 meter maybe? I'm betting 'yes'.
You should measure at where you sit to get the real response you're hearing. No way the left and right mains are the same much less either being flat.

That left speakers esp. being right exactly in the very corner of the room is a pretty big flaw -even more so with the right speaker being far from a side wall. Both aiming directly forward.

If you could place some filler in those built in wall shelf sections where you elec. and RP are that should help too since there's probably a lot of sound bouncing around in there. I've heard the effect of those 'nooks' in several rooms -always messy.

I hope when you work with the Dynaudio drivers (very good drivers BTW) you build cabinets that can be placed far from the walls. In-walls aren't high end.
It's hard enough to distance the room effects from speakers, but impossible when you actually couple the speakers to the walls themselves.

The B-G ribbons have a poor high end, but otherwise very highly regarded.
In themselves they're dipoles not monopoles though.

Some companies that use them in cabinets making them monopoles and also add small spiral ribbon tweeters to the take over the very high range. Genesis is one I think. Most use them in their open dipole state.

I have Newfrom Research and thier 45" ribbon (actually three 15" ribbons in one solid heavy steel case) is actually a monopole design (a 'must' IMO), flat +/-1db from it's 1000Hz x-over to ~16,000Hz, and only down another 1db at ~20Khz (slow smooth roll off beyond that).

To have near perfect response in this ribbon, they can't play as low as the B-G's, but they're mated to dual Scan Speak 8545's carbonfiber/pulp cones. These are one of the best drivers in the world, and blend seamlessly (once broken in) to the ribbons.
See their use in the $10K range Wilson WATT, ProAc, Nova, Vienna Acoustics, etc...
Flat down to ~30Hz (due to one of the lowest res. freq. of any 6 1/2" driver).
Only a ~30 degree phase shift through the x-over too.

You can buy the ribbons alone from Newform and the drivers from Parts Express, but the Newform 'kits' are about the same price and you'll get everything at once.
There's better x-over designs than Newform uses though available online (Yahoo forum).

If you still wanted in-walls you could mount the ribbons to the edge of the TV notch corners, and mount the woofers in the wall area next to them. That would be a much better distance (~6-8' tops for the best imaging in pretty much all speakers), but I highly rec. you use an actual in room design and put up some wall treatments.

In that white room you could have some long white heavy curtians with a layer of very light translucent cloth (very pretty for high SAP factor -heh) at the first reflections points which would work great to dampen echoes and not look like a geeky 'audio tweak'.

Throw a blanket over your RP when you listen to music too. Big help in getting rid of that big plastic audio reflector that an RP screen is.

I have a nice looking one that's set w/ weights on top of my RP so I can just flip in up or down whenever I need to.

Good luck

My understanding of the high frequency rolloff on the BGs was that it was due to the line source being mic'd at such a close distance - that frequency response farther away (depending on the length of the ribbon) would exhibit better response. Is this a flawed understanding?

They make a driver (D22??) with a 1" dome tweeter that has no minimum listening distance.

Apparently Charlie is an engineer, and from my experience engineers are a little different from the rest of us (no offense, Charlie). They literally want to measure everything and leave out anything that is not measurable. That is just the way they are, and the way they have been trained.

That has its advantages, of course, and without engineers we would have no audio toys to play with, except maybe a toy drum! But engineers characteristically have problems seeing shades of gray, or making subjective judgements - because they can't measure it, I guess.

I personally prefer to be rational as much as possible, and I consider myself an objectivist in the audio arena. But, and here it comes, I definitely hear audible differences between amplifiers. My speakers are unusually accurate (Digital Phase) and as a result I may hear subleties missed by some, and my hearing checked out as "good for a man your age" a couple years ago (I am 57).

Anyway, here are some of the amps I have auditioned in my system (preamp is the Citation 7.0):

H/K PA5800 (still using in a backup capacity)

Carver 705X (dull sounding)

Citation 7.1 (hurt my ears so bad I had to go to an audio specialist - I'm not kidding, that is when I was tested).

H/K Signature 2.1/1.5 (these sound the same - nice for their price but lacking enough that I did not want to keep)

Bryston 4BST (so well considered by all I had to try it and it sounds very neutral and detailed, but had a bit of an edge and lacked something musical. After about 15 minutes I didn't want to listen anymore)

Chiro C-500 (when Kinergetics went under I got this new and cheap and for several months it was in my system and sounded great. Very smooth, with good detail and plenty of dynamics. Makes everything sound god, but prone to a little hum and I have traded it)

Marsh A200S (wanted to try this after reading such good reviews, and it does sound good - very detailed, almost bright but not quite, a little lacking in the bass. I would have kept it except for the next amp)

Innersound ESL (this is the one that I love; the best I have heard to date. It is neutral as the Bryston and almost as detailed but with none of the edginess - just smooth and extremely dynamic. Puts out 300w/8ohms, 600w/4 ohms and 1200w/2 ohms. Also very very quiet, and designed to power electrostatic speakers (ESL makes those also). Now here is the kicker - it idles at 3 (yes three) watts! It runs very very cool and I leave it on all the time - there is no switch on the front. It is not digital, and even though I read their white paper I still don't quite understand how they get this much clean power out of a 42 lb amp. It is also beautiful to boot. Regular price is $3,000 but I was lucky to get a return unit (guy wanted the older model with a switch in front) for much less with full warranty. The amp is sourced by Coda Technologies, one of the top audio manufacturers and build quality is high end all the way. Anyone interested can go to innersound.net for the info. They also make a multichannel model with slightly lower power ratings. Oh, yes, they also make 1,000 watt (@ 8 ohms) monoblocks if you need that much power.

dsmith901



[This message has been edited by dsmith901 (edited September 19, 2002).]

I accidentally quoted azryan and could not delete the post. Please forgive me Azryan