Finding room for RS1B's!

[phaedrus]

but whaddya guys think about the alternative of running all the EMIMs together over the combined frequency range? i know it's been suggested one or twice before, at least for the RSIIb if not the 1b, but i don't know if it's been tried.

This approach has been tried before, most notably by the sometimes-AK member who "improved" the RS1s by replacing the EMIMs and crafting a simple three way crossover with all the midranges driven simultaneously. He was so modest as to suggest Arnie didn't know what he was doing when he designed the original crossover.

I admit I sometimes get a little frustrated with all the proposed crossover "improvements" to these older Infinities. Arnie & Co. didn't design these extremely complicated 5 way crossovers because they were too stupid to cobble together a 2 or 3 way crossover, they did it because they were working to a very specific design goal.

Can you wire all the EMIMs together in a single array? Sure. Will it sound different? Undoubtedly. Will it sound better? Dunno, but somehow I doubt it.

David

 

[cdfac]

yes, these were my concerns as well with modifying the original concept. i really like the imaging as-is (except for the wavering caused by the aging passive XOs), so i probably won't think too seriously about trying that out for a while.

i hope i never gave the impression that i knew better infinity's designers. as a single owner, however, i do have fewer restrictions on what i can do to improve performance. for example, infinity would never seriously consider a configuration that would require the owner to actively triamp, even if that gave a modest performance increase. as it is, the main reason i even started considering the path i'm on now is because: a) i feel the lower EMIMs are crossed too low for comfort, especially during loud dynamic passages, b) it's quite expensive to properly rebuild the passive XOs, and even still there will be certain drawbacks compared to an active XO, and c) i really fell in love with the sound from my BX-1 monoblocks, which unfortunately are on the low end of the acceptable power range for the mid/hi panels in the stock config.

i think right now i will just stick with my original plan of separately powering the lower EMIMs and modifying the upper EMIM circuit to be LP only. i bought the 4-way Ashly XR-4001 active XO to try out, with the intention of eventually getting a sub like the VMPS New Larger to handle things way down low. nothing i try will be very difficult to undo, fortunately.

 

[Arkay]

Clearly (to my mind and ears) the original Infinity crossover design should be superior. If you delay the sound coming from the further-out drivers slightly, compared to the sound coming from the center driver, you effectively simulate the sound coming from a(n imagined) point source, which is universally accepted as the sonic ideal. Line array speakers are fantastic, but time-aligned line arrays with such delays, are even more so.

That is the theory... does it work in practice? Presumably it depends on how well the engineers approach the sonic ideal, in actual performance. Did the Infinity designers get close enough? My ears suggest "Yes!" ...but I've never bastardized an Infinity speaker to do a rigorous A/B comparison. I'd be reluctant to do so, as I seriously doubt it would afford any improvement. You're actually moving from a theoretically superior design to a theoretically inferior one. Why do that, unless there is reason to suspect that the execution was flawed?

 

[phaedrus]

i hope i never gave the impression that i knew better infinity's designers.

That wasn't directed at you, Chris. I was specifically thinking of another poster. I just think it's unlikely that there's more than a handful of people on AK whose knowledge of crossover design can match the original Infinity designers', and that we therefore ought to be cautious when modifying these things.

David

 

[cdfac]

arkay, hadn't even thought of your first point. is there such a delayed line array on the market? that would be very interesting to hear.

just to make things clear, all of the changes i'm tentatively undertaking at this point are either leaving the essence of the original design intact or echoing improvements that infinity made later in the IRS Beta's. i very much believe that Arnie et al either knew what he was doing in the first place or quickly learned from his mistakes. i wouldn't go through the trouble of all this fidgeting if i wasn't impressed enough already to think these speakers couldn't possibly keep me satisfied until a pair of IRS V's fall into my lap.

 

[Arkay]

arkay, hadn't even thought of your first point. is there such a delayed line array on the market? that would be very interesting to hear.

just to make things clear, all of the changes i'm tentatively undertaking at this point are either leaving the essence of the original design intact or echoing improvements that infinity made later in the IRS Beta's. i very much believe that Arnie et al either knew what he was doing in the first place or quickly learned from his mistakes. i wouldn't go through the trouble of all this fidgeting if i wasn't impressed enough already to think these speakers couldn't possibly keep me satisfied until a pair of IRS V's fall into my lap.

I had in mind the three midrange drivers on the original RS IIs, when I wrote about the time delays. It is my understanding that these work on that principle, although I might be wrong.

I completely agree with your comments about the 1B's being satisfactory until IRS V's come along. I always figure the V's are the ultimate "dream score", but the ones I more realistically hope to find one day are the 1Bs. They are the eventual "real world" goal, for me, although HOPE for IRS Vs never completely dies, either. You're a lucky man already, to have a set of those 1Bs!

 

[NumbDiver]

Just a thought.

Some of the top designers of current and past equipment have helped out on this and other forums. I've read many strings from Nelson Pass, Roger Modjeski, Bob Carver and others on how to improve their original designs (remember, they were stuck within the parameters of the year they made them, as well as a price-point).

Has anyone tried to contact Arnie and ask his opinion? We all consider him a God (I know I do), but there are certainly a few AK'ers up to the task of having an intellegent conversation with him regarding building an improved crossover, etc.

Has anyone tried to get someone like Arnie to AK fest as well? If I had designed and built some equipment 20+ years ago, and that equipment had a cult following, I would be honored to try and help that group keep and improve my best efforts.

Just an idea. :scratch2:

 

[Ken Boyd]

I will add my two cents here although you all sound much more tech minded then me. On one pair of RS-1b's I am running an active crossover and I simply set my crossover point on my low cut off higher than Infinity's crossover. That eliminates the concern you have with the lower frequencies driving your EMIM's to hard doesn't it? I let the Bass tower handle a little more of the lower-mid loads by letting them handle a little more of the mid bass. The manual says that the orginal crossovers Low Pass Cutoff in the high 1 position is 250hz so why could you not set your crossover point at 300 or 400hz and let the bass drivers handle below that. And if you want to use a seperate sub, could you just use one of your secondary outputs from your pre amp and go straight to a Mono Block Amp to power a sub for anything under the lowerest cut off point of 22hz.

I also have a Rack set up with SAE equipment and I have the SAE 2800 Parametric Equalizer and it doesn't just have a simple setup of octive db gains but it has frequency's, bandwidth, Levels and attenuators. I have installed it since the SAE preamp that I use, the 2100L has no controls for bass, mids, or treble and I am using that on my Quantum speakers and I find it so much more effective and fun to play with than a simple equalizer. It also has a cutout switch than you can use to just go back to flat if you want to. I love playing with that unit.

I am also watching that set of bass towers but am thinking of instead of those, purchasing another set of the QLS-1's from a guy that I have made an offer to. I really like those as I find that although the RS-1b's of mine give what I think is a better soundstage and imaging I like the way the QLS-1's sound in the upper range, I think they play the hi's better. I have both the RS-1b's and a Pair of QLS'1's hooked up in the same room and have been doing some comparisons and I don't think for my taste I need more bass on my RS-1b's as much as I would rather have another pair of QLS-1's. If anything I would pair those bass towers to my QLS-1's for fun. I could run off my preamp output b and run those bass towers on a pair of amps to handle more lows. Those crowns have the PIP slots where you can program the amps to just put out signals in a programed frequency so you wouldn't even need a crossover and I could use the attenuators on the back to set the output levels of the bass towers to my taste so as not to over power the mids and highs of the QLS-1's

But Cdfac I thought you pretty much had gotten all the bugs worked out on your pair of RS-1b's and liked them? Are their still some major shortcomings on them that makes you want work on them more? I find right now my most major problem is finding new music that I haven't already listened to a million times to just enjoy them. Does anyone else have that problem? My mail man problem wonders why so many packages from Amazon comes in each week, as I am constantly in search for new artist whom I enjoy to listen. This week I have completely varied from my usual taste and have been buying lots of music from bands from Finland, and Norway that Gothic Sypmphonic Operatic heavy metal stuff. Its amazing to me how much I like that type of music everything but that Gothic Growl which I have to over look sometimes as its in all of that music.

 

[Ken Boyd]

By the way Someguy on Ebay has a pair of Gamma's for sell, ends in about a week and is at 2500 right now.

 

[Ken Boyd]

And a pair of RS 2.5's as well just came up kind of rough but look like an easy restore pair, and he only want's 799 BIN or best offer. That seems like a good deal to me, I would snag them if they were a pair of 4.5's. But to be honest I kind of think those 2.5''s and 4.5's are ugly, and I really don't care for oak, I have to put up with oak on my RS-1's as hard as that is.

 

[cdfac]

i may change my mind when i get my PC5002M back, but i find that the 1b bass just isn't what i want. i think everything is working correctly, but the QLS1s spoiled me in that area - perhaps the new room location has a large part to do with it, too. i'm probably being incredibly picky, but those Watkins with the big Yamaha were magic. from 250Hz or so on up, it's not contest that the 1b's are better speakers, and i don't see why with a little work i shouldn't make them better throughout the entire audible range. they just need deeper, wide-open bass to match with the huge, wide-open mids and highs.

 

[Ken Boyd]

Hey did you get you Yamaha amp back, and are you happy with the sound? If not maybe you can just run a real good sub for the deep bass. If I recall, the Infinity uses a 25 hz limit to the bass towers so if you set up a sub from 25 hz and lower you should be able to get that very low bass you want.

 

[Army]

Chris I still have a spare SpecII you could borrow till you get the yamaha back. All you'd have to do is come get it. :thmbsp:

 

[cdfac]

might just have to do that, scott! i'm getting the Yamaha back soon, but then I may be short again. we'll see.

ken, i'm most likely going to try a sub at some point. i probably will cross it in higher than 25Hz, though. it's not just the lack of super-low bass i hear, there are other issues as well. the bass just doesn't sound as natural as the QLS1's. i think they made the woofer towers too small. the servo/EQ does a pretty good job of combating that, which is why you hear deeper bass when you use it, but it's an imperfect solution. from what i understand, the later servos with the accelerometers are more natural sounding. now, it could be that i haven't experimented enough with the XO settings. i will be needing an SPL meter pretty soon here anyway, so i should probably check that i'm at least getting the best bass i can in stock form.

 

[Ken Boyd]

I take it your name is Chris, did you sell your QLS-1's? I was wondering if yours was the pair on Audiogon. I bet that was hard to do, as I am torn between which ones I like best. I didn't think I would like the QLS's as much as the RS-1's but after having them both I would hate to deceide which to part with. But I got a nice replacement Watkins DVC driver to replace the one that had a bad voice coil. I have been using a spare one I had but it was the paper type not the poly type that was orginally in the pair I have. The guy says its like brand new. Also got some new little pegs to hold the grills on the RS-1's, just in case spares.