Infinity Speakers
RS-8/RS-8a
Specifications
- 1" soft dome tweeter
- 6.5" mid-woofer
- 10" powered subwoofer, side-firing
The rear-mounted amplifier sports a very long heatsink that is the largest I've seen in a powered speaker yet, which was surprising because the amplifier is rated for "only" 150 watts. This is perhaps because the speaker utilizes class A/B amplification?
Compare this to, for example, BP7002/BP7004/BP7006 amplifiers that have no external heatsink at all (but they do have a small heatsink on the power PCB that dissipates into the inside of the cabinet).
Repair Notes
I bought these speakers with one amplifier barely functioning and the other functioning at what my impression was half volume.
After removing and testing the amplifiers, I found that all of the capacitors were out of spec ESR-wise. The power boards definitely needed to be recapped, and I recapped preamp boards for good measure (in case they would sound better).
Originally I thought that the half-volume speaker had something wrong with the level settings from the factory, and tried to adjust the values of resistors that bring speaker level input down to line level, but the issue was the dead capacitors. No changes to the component values was needed.
After the repair I have the subwoofers set to about 3/4 volume and they produce a lot of bass. I think the factory attenuation from speaker level is fine.
Listening Impressions
I am impressed by the low frequency performance of these speakers. The bass to me extends very low, on par with Definitive BP7002 even though BP7002 have 12" drivers plus 2x 12" radiators. The bass has excellent slam but is not boomy and isn't "stuck on". I can distinguish individual kick drum strikes in symphonic metal that are smudged together on lesser speakers.
The midrange I think is quite nice. Listening just to the RS-8s, I hear no issues with it. Comparing to BP7002 I believe BP7002 has more midrange, thus perhaps RS-8 midrange is slightly pulled back. Perhaps this is also a transition speaker from "vintage" sound with a lot of midrange to the"modern" sound which is EQ'd more like a smiley face.
The treble, unfortunately, is dirty and this ruins the speaker overall for me. I wonder if the problem is in the crossover but as it is the treble dirt is just too much.
Update: listening to RS-8 again, they have less treble dirt on EDM material compared to acoustic recordings like rock. Rock is still very obviously dirty. Some EDM is noticeably dirty, some sounds fine, especially at lower volumes. I don't know if this is a case of the speaker faithfully reproducing the garbage that is present in the recording or the speaker being overloaded by acoustic material. The latter seems not too likely as generally EDM has more complexity, since it is not limited by two hands and two feet of the drummer.
Update 2/26/24: I hear primarily treble dirt, followed by what I would call treble harshness (but dirt predominates). Bass quantity is I would say more than sufficient with the amplifiers repaired and volume turned up all the way, for balanced reproduction bass shouldn't be turned up to the max. Low frequency extension is subjectively quite good but I'm listening in the living room which has very good low frequency gain on any speaker. RS-8 do not sound boomy, I do not perceive elevated mid- or upper bass. These might be really nice speakers with better tweeters.
Composition Overture II aka OVTR-2
Specifications:
- 1" soft dome tweeter
- 2x 5.25" mid-woofers
- 6.5" powered front-firing woofer
- 6.5" powered rear-firing woofer
- Bottom-firing port
These speakers use the same exact tweeter as RS-8/RS-8a (333232-001). This tweeter is also used in a number of other Inifnity models with 2003.X model numbers.
The Overture II have a strange configuration. Is it really necessary to have two 5.25" midranges for a single 6.5" woofer? Seems like more of a marketing ploy to get the money of "more is better" crowd that listen mainly to classical music, since the 6.5" woofers do not have much low frequency extension.
Repair Notes
My Overtures came with non-working amplifiers. In both speakers one of the R43/R43B resistors was open, and the other had a higher than specified measured value. Due to this the speaker relay was not activating as it was seeing less than the needed voltage across its coil, resulting in no sound output.
I also found the majority of electrolytic capacitors in the power supply area of the board either significantly out of spec on ESR or open. I replaced all of them for good measure, I believe they are not in audio path but perhaps their lack of function would contribute noise to the amplifier overall which they are meant to filter.
The amplifiers are somewhat unconventional - they use 200 V MOSFETs as power devices and as such have no power transformers at all. Supply voltage for the amplifier is +160 V, with some components running on +24 V. There is a transformer that, I'm guessing, isolates incoming audio input from the rest of the amplifier, to prevent electric shock via speaker terminals should anything in the amplifier be shorted.
Due to the high supply voltage, the amplifier uses several 63 V and 100 V capacitors. I had some 63 V ones but I didn't have any 100 V capacitors of the needed values.
Listening Impressions
As one might expect, 6.5" woofers do not play very low. They do play something and they can be turned up with the knob on the front of the cabinet. When turned up, predictably, the speaker produces a good amount of mid/upper-bass but still doesn't play low. Maybe this speaker is aimed at people listening to classical material or jazz who want a bit more of low frequencies, but it certainly does not pass muster for EDM.
I don't think the bass can be made excessively loud. Perhaps adjusting resistor values on the amplifier would produce more prodigiuous bass output, but in the factory configuration the bass was never overpowering.
The cabinets have a bottom-firing port which couples the speakers to the floor and makes the floor vibrate. Kick drum is felt, mildly (not as prominently as with a dedicated subwoofer with larger drivers, such as Definitive ProSub 1000).
I had the Overtures on the dead tweeters (one half dead and one 90% dead). They sounded very dirty in the treble, which was not surprising. I thought some of the dirt extended lower in the frequency range but this isn't a scientific measurement. Perhaps the midranges were fine.
Speaking of midrange, the Overtures have a lot of it, as one might expect given the driver assortment. With working tweeters it is probably a good speaker for acoustic music or vocal material.
I did not bother installing working tweeters into the pair because I knew I wouldn't be keeping them given the bass output.