jmschnur said:
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I am intersted to hear about forum members use of equalizers and or crossovers in their system. I would not expect these to be needed for good listeing rooms and the higher end of Martin Logan's product line-but I wonder if some of you have used either or both. If so, what has been your experience with them, and what have you used?
Joel
Hi Joel,
Around here, I’m probably the most extreme in terms of use of EQ and external crossovers, so I’ll chime in. I’m sure you’ll hear a counterpoint or two as well
Fixing a room issue with EQ is indeed the last resort, but it is not evil in my book. For instance, my room was custom designed around my Martin Logan speakers and it is acoustically treated with RPG products. So I started from an ideal foundation. However, I do very meticulous room calibration with measurement software and a calibrated mic. As is true in even the best rooms, there are ‘issues’ at frequencies under 400hz. Addressing these ‘issues’ eventually will require some amount of EQ, usually some very judicious cuts, rarely a boost (and if boosting, never more than 2 or 3 db).
Besides frequency domain, there are time and phase issues that can be introduced with blending with the sub and other speakers. However, your DC-1 should let you carefully adjust delays, but does it let you adjust phase to the sub? If not, does your sub have phase controls? You might find that the 125hz issue is due to phase integration between the Clarity and the Sub.
Once you’ve ascertained that the sub to mains integration is adjusted as best as possible with the tools at hand, and you still have an issue, then yes, it’s time to consider some external help.
Introducing any kind of post-processing after the surround processor is a big leap, and given the revealing quality of these speakers, you want to use good equipment.
If you want to really enhance the system, I’d recommend the
DEQX system. It will do not only the EQ but will also provide room correction (in phase and time domains as well). Not cheap, but incredibly effective. Hearing a DEQX calibrated system before and after is mind-blowing. Makes talk of cables and other tweaks seem totally irrelevant.
Or the ultimate is go to a Meridian G68 with their built-in room correction and a totally awesome surround sound proc (or step up to a Lexicon MC-12 v5).
If the gold-plated solution is not your cup of tea, then in descending order of cost, here are your alternatives:
External EQ/Crossover for the mains: This assumes you will also bi-amp your ML’s and go full active crossover (and bypass the passives in the speaker). Use a DBX DriveRack 260 speaker processor to perform mid to high crossover and to supply parametric EQ, delays and phase adjustments on each output. This is the ultimate in flexibility and really surpasses anything the factory can do with passives. You also benefit from bi-amping and can use your favorite type of amp for the bass and the panels.
A simpler approach is to simply EQ the mains with a straight up parametric EQ. There are many choices here. Most are from the pro-audio side, which works really well IF you take care to manage the unbalanced to balanced matching between consumer and pro gear. Some Jensen ISO-Max transformers are the key to success (and low-noise) here. Read upon this review of the
Behringer Ultracurve 2496
You could also look into other pro-audio effects units that feature parametric EQ (some from lexicon, see the MX series).
The pure analog (and cheap) route is to just get two of the
PreSonus 3 band parametric EQ’s some RCA to TRS (unbalanced) cables and give it a shot. For under $300 total, you can determine if the fix for the frequency domain is worth the penalties (albeit very slight) in terms of S/N ratio.
To see what I’ve done, go read up on how I use a speaker processor over on
my site. The results are amazing.