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Update on new EMIT/EMIM Diaphragms

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I run my 4.5's active, 110hz vocal classical orchrestral, 156hz hard rock, listening level ussaually between 50 to 90db, which is still loud in a quite enviroment
 
Maxamillion said:
If the 4.5 is like the RSIIb, the Infinity data sheets say they cross at 150Hz, but they actually cross at ~250Hz with the passive crossovers, based on my measurements.
Click to expand...

RS-1b crosses over at 140Hz

IRS crosses over at 70Hz

RS-2A crosses over at 175Hz
RS-2B crosses over at 150Hz
 
rabbit said:
RS-1b crosses over at 140Hz

IRS crosses over at 70Hz

RS-2A crosses over at 175Hz
RS-2B crosses over at 150Hz
Click to expand...


That's what they say in the spec sheets, but that's not what I measured in my RSIIbs using TrueRTA and pink noise. The low EMIMs roll off and the woofers roll in at ~250Hz using the passive crossovers. The low EMIMs are down ~25dB at 150Hz!
 
Maxamillion said:
The low EMIMs roll off and the woofers roll in at ~250Hz using the passive crossovers. The low EMIMs are down ~25dB at 150Hz!
Click to expand...

very interesting. that means something else is dropping the low end of the EMIMs other than the crossover, since that's only 12dB/octave. part of it's probably natural roll-off, so is the rest primarily dipole cancellation?
 
rabbit said:
RS-1b crosses over at 140Hz

IRS crosses over at 70Hz

RS-2A crosses over at 175Hz
RS-2B crosses over at 150Hz
Click to expand...

I thought the RS-1b's crossover points are based on user selected crossover points on the Infinity active crossover? According to my user manual page 8 it states "The Low pass cutoff control (#3 of figure 4) sets teh lower limit upper limit of the woofers: 100hz in the "Low" position, 150 Hz in the "Flat" position, 200 hz in the "High 1" position, 250 Hz in the "High 2" position". I was under the impression that meant that it also effected the point at which the EMIT"s rolled on. So am I understanding that no matter which selection you make on the Low Pass cutoff control the EMIM's are always set to roll on at 140 Hz and that the bass drivers and the EMIM's will both be covering the some of the same spectrum? Say if you have your Low pass cutoff control set at High 2 that the bass drivers will cutoff at 250 Hz but the EMIM's are still covering the spectrum from 140 Hz to what ever point the EMIT's crossover. One other thing I was in question of was the units amps input impedence control, the first control allows for user controls from 25K to 200K input impedance for the mid hi level amp, yet my amps input impedance is 10k impedance in unbalanced input. The manual says if the input impedences listed in the amps owners manual is other than one of the values listed at the control call Infinity's custome service department for instructions. Pior to that it states that the amp input impedence (Z) control puts the appropriate value of the capacitor in series with the input of the mid/high frequency power amplifier. This gives the proper crossover frequency for the mid/hi sections. Anyone know what effects might be caused by having an amp with a lower than selectable impdeance on the Z control?
 
if the actual input impedance is below the lowest selectable value, then your EMIM's are rolling in a bit higher than 150Hz or whatever. likewise, if you set the dial to below your amp's actual input impedance, they'll be getting lower than 150Hz. you can hear this quite easily if you move the dial with music playing.

but it's more complicated than that because that roll-in is only 6dB/octave, while there is still the fixed 12dB/octave passive crossover at whatever frequency (presumably ~150Hz but who knows with these yahoos!). so if the active isn't set to the right impedance value, then you'll get a shelved response, in the same way that the RS4.5 equalizer lets you adjust for different frequencies for the lows and highs.
 
Well the lowest setting on the Infinity active crossover impedence is 25k and my amps input impedence is 10k in the un-balanced imput so their is no way I can set the Z selector for less than the amps input impedence. But my amps input impedence is 20k in the balance input so probably I should try and use that as it is closer to the actual values that are allowable on the Infinity control. I do not know if maybe putting some kind of resistor in line prior to my amps input to raise the impedence, and it that my create a problem. But I have not had any problems with anything with the Z selector set at 25k.
 
Thought you might be interested in my latest measurements/tweaks. I have adjusted the levels on the high mids and tweeters to give the sound I like best and to match the two speakers as closely as possible, producing the following plot. The blue trace is the right speaker alone, the red trace is the left speaker alone, and the green trace is the combined response for both speakers. All measurements are in-room, made with pink noise and measured from the listening position. I like the gentle downward slope of ~5dB from 20Hz to 20kHz better than a completely flat response.

I think the left and right match extremely well. The level control for the high mids was set to 1.9ohms for both the left and right speaker, indicating that the Graz diaphragms (and my crossovers!) match very well.

I have gone ahead and ordered Duelund graphite resistors for the high mid and rear tweeter circuits to replace the high mid pot and rear tweeter sand-cast resistor, since I don't intend to change anything else in those circuits. Since the midrange pot is rated at 15W I ordered two 3.9ohm 10W Duelund resistors to be installed in parallel to make one 1.95ohm, 20W resistor.

I am leaving the pots in place for the low and high tweeters in anticipation of Graz making EMIT diaphragms - no sense putting fixed resistors in there until I know what the optimum values will be for his units.
 

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damn, much more than i was hoping for unfortunately. guess i'll be dreaming for a while :smoke:

EDIT: i should mention that i'm looking at it from an upgrade standpoint when i say that, not a replacement standpoint, and my current speakers have 8 EMIMs total. from the latter viewpoint, they seem pretty reasonable, akin to the new Watkins production run. i really appreciate Graz doing this regardless!
 
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my bad they use 1.5 inch domes . Got them confuse with the EMITs. But I do need the tinsels reattached. A drop out replacement would be great for these.Anyone have any suggestions?
 
cdfac said:
damn, much more than i was hoping for unfortunately. guess i'll be dreaming for a while :smoke:

EDIT: i should mention that i'm looking at it from an upgrade standpoint when i say that, not a replacement standpoint, and my current speakers have 8 EMIMs total. from the latter viewpoint, they seem pretty reasonable, akin to the new Watkins production run. i really appreciate Graz doing this regardless!
Click to expand...

Ditto I just can not see me be able to justify 14 of them for my speakers 4.5s and IIbs
 
total bullcrap, someone here just started seeing $$$$$$$$$$ instead of his indicated fair wage formula.
 
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Can't say I'm surprised by some of the reactions, but I am disappointed.

We asked him to make these, and he made them to his exacting Apogee standards, because that is what his reputation is founded on. The originals were farmed out to some third world assembly plant where the $0.10 per hour workers made them, and Infinity sold them to support their thriving speaker business, not to make their primary income. These units are CNC machined and hand assembled by his small team of expert workers, and have tolerances more than 20X better than the stock. More importantly, they sound much better than the stock units.

I don't blame some for being disappointed at the price, but I would ask that you refrain from personal attacks on the man.
 
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