Optimus Pro 4000

Discussion in 'Speakers' started by amante, Sep 1, 2013.

  1. amante

    amante Member

    It's the end of summer and I got pulled away from posting on AudioKarma until now. Here goes:

    I was given (could not refuse) two Optimus Pro 4000 speakers which I knew nothing about other than they are grandkids to my Realistic Mach One speakers. They are nearly the same exterior dimensions to the Mach One...perhaps a couple inches more interior room since there is no dividing board as in the Mach One. Also, the exterior veneer seems thinner but nicer color than the Mach One. The crossover board is nicely marked and better organized, too. To be short, I ran out of time this summer and simply replaced one capacitor from a 33uF to a 14uF. Everything else appeared to still be in good shape. If I do go back in and replace caps then that will be major surgery as today's caps will consume a lot of space not planned on by this circuit board.

    Sound impressions: By themselves, the Pro 4000 sound powerful, accurate with plenty of bass and so - so imaging. (Reminder: My Mach Ones have the first Videolady upgrade and thus pretty good imaging.) Personally, they are a tad brighter than I prefer but not painfully so. This is where I wish they had adjustment knobs like the Mach One. So, if I were to make a decisión between either the Pro 4000 or the Mach One I would defer to the Mach One...but only slightly...they are cousins, after all.

    SURPRISE: So, I decided to do some minor construction in my basement and just stacked the speakers playing all sorts of Classical music, Rock and a few soundtracks...OMG! When I cranked up the volume I realized they compliment each other and sound very much like another single unit I hadn't heard in a year...an AR9! Yes, I definitely know what AR9 babies sound like for all the drooling I've done...plus I have colleagues nearby to verify and so, because of this, I thought I should pass this information onto you kind folks. I suppose this would be a cheaper, higher sensitivity rating version of getting to that mountaintop and full bodied AR9 sound.

    Attached Files:

  2. amante

    amante Member

    Optimus Pro 4000 mod

    Well, I grew a few speakers again since my earlier post and while I liked these speakers I wanted to sell them to someone who had the room and need. Unfortunately, I had no takers which surprised me. So I thought if they're staying under my roof then I would improve the midrange and give them to one of my kids to get kicked out of college with.

    The midrange sounded recessed...too polite...so I copied ideas from the Mach Two followers. I bought a Pyle midrange (PDMW5) that was an easy drop in, removed the HUGE cup glued behind the original midrange for additional bass and stuffed that mid area with filling. Oh, and I also loosely stuffed the port after playing with various positions...you can see it rolled in the pic. (FYI, with the port open the bass sounded a little muddy, with the filling pushed in all the way it killed some of the bass and thus I have it rolled almost to the outer lip for what I thought sounded best, a leaky enclosure like Bozak.)

    It sounds pretty terrific...not quite as good as my very best speakers which have ultimate imaging but these are now in the ball park. They sound very balanced, the bass is punchy instead of muddy, the midrange is pretty impressive and the treble is clear although almost not strong enough compared to the other drivers but that's not quite a complaint.

    So, while I wish someone better than myself had done an honest engineers reconfig of the crossover this easy fix makes it an accurate speaker with deep bass. (I kept the original mids and holes for that day.) Don't walk past these!

    Attached Files:

  3. Copa1934

    Copa1934 My ears are bleeding Subscriber

    Interesting, but removed the cup? What's protecting the mid from the pounding of the woofer?
  4. Lavane

    Lavane Super Member

    I was wondering the same thing. :scratch2:
  5. RickeyM

    RickeyM AK Subscriber Subscriber

    When I put the Pyle's into my Mach Two's, I left those cups in place. I figured the little extra volume with them removed wouldn't help the bass any and since the Pyle PDMW5 wasn't handling any deep bass, being in that cup wouldn't hurt. Besides, when playing loudly, I plug the ports on my Mach Two's and without the cups in place, the Pyle 5's would suffer much abuse from the big 15's :D

    But hey, glad you like the results from the PDMW5's :thmbsp:
    Last edited: Dec 5, 2013
  6. amante

    amante Member


    :yes: Guys, thanks for keeping me honest! I only did one speaker so it was no problem to put the cup back in. I suppose I would have noticed chaos if I had really turned up the volume instead of where I normally have it. Only new thing to report is that I took the nasty yellow fiberglass patch out of the port and put it back in the cup...replaced the port filling with a small puff of cheap pillow stuffing like filler...I think it made an improvement(?).

    I need to get myself a meter. I swear these are sounding a little deeper than my Mach Ones which already go very low! Going through my familiar CDs right now to confirm.

    One last thing, these Pyle midranges are actually pretty darn good! :thmbsp:
  7. -reverb-

    -reverb- Member: Cult-DCM Subscriber

    I had a chance to get a pair of these about a year ago for next to nothing. That's about what I needed to spend on speakers at the time so I passed. Damnit! It's always the ones that get away that you come back to haunt you. I knew I should have at the time - needed foam, needed TLC on the veneer but.....

    Think I still have the contact. Wonder if he still has them :scratch2:
  8. amante

    amante Member

    Get them!

    -reverb-, if they're still available I would go for them. :yes:

    Last night and today I listened through several of my familiar low frequency CDs (TelArc pipe organ recordings, a few soundtracks that dip such as anything written by James Horner and TelArc Star Tracks 1 & 2) and these definitely go a little lower than my VL modified Mach Ones. The only way to go any lower than these speakers is to move up the food chain like AR9s for much more $$$. That said, my musical interests are choral, jazz and Classic rock and am keeping my main set ups as they are. So, I'll keep these but will probably pass them on to my musical teenage kid who'll appreciate them. -reverb-, if your B channel is free then pop in a pair of these and please report back.

    In short: Optimus Pro 4000 qualify for handling ultra low frequencies! :thmbsp:

    "She's fast enough for you, old man." -Han Solo
  9. Copa1934

    Copa1934 My ears are bleeding Subscriber

    Curious as to how you gauge "low". For me I really noticed the difference in Mach One and Mach Two when kicked back in my ergo chair and eyes closed. What I sensed and what I heard were different. What I sensed was the Mach One tended to go deeper and the Mach Two a fuller mid-bass. I would attribute the latter to more "useable" cabinet volume AND porting. The Mach One tend to be tighter. Same can be said of my AR3a speakers, having stronger Mid-bass but not going as deep as the Mach One or Mach Two. Keeping in mind, of course, the Mach speakers are 15" drivers, though really they're not, more like 13-14".

    I'll have to pair mine up again some day. Room acoustics change things, as do placement. Only know that when I pair the Mach One with Mach Two or AR3a the fullness of sound is quite enjoyable.
  10. amante

    amante Member

    low versus low

    Hi Copa1934,

    My sense of low comes from two points...low rumbling in my familiar listening room and from the several pipe organ CDs I've come to own/know very well from when I was an undergrad church music major. I'm no sonic engineer but I've been around pipe organs and I know that particular rumble. These slightly modded Optimus Pro 4000s definitely brought out more l.f. from the king of instruments. That said, I agree with you about acoustic suspension bass accuracy and these Optimus will not displace my Mach Ones for only a tiny frequency addition.

    One thing I would mention, I was wrong about the size of the 4000 compared to the Mach Ones. While they are alike in width and depth, I didn't notice that the 4000 is taller. The Machs are 28" tall (exterior) and the 4000s are 31.5" tall (exterior). Sure the wood is thicker on the 4000s but with the 4000s not having an interior plank dividing the cabin interior and with them being ported these may make differences.

    BTW, my 17 year old son felt our DCM Timewindow 1s go lower and more smoothly than the Optimus Pro 4000...and he's right. (They're both hooked up together in a basement HT.) So, while these Optimus Pro 4000 babies are way better than say Kenwood KL or kabuki speakers they are still middle level until someone improves the crossover numbers. And unfortunately, I'm still going to lose a pair of Timewindows to college soon, ha, ha.
  11. Copa1934

    Copa1934 My ears are bleeding Subscriber

    Cool. One thing all the Machs from II on, benefit from is more usable volume AND of course porting. Did you open the mid chamber for you Mach One? I opened mine and noticed a solid improvement, though more in mid bass. However, with one, only, I ADDED volume to the rear, using the mid chamber access. Removed the cover entirely, then added on another 1cuft. That speaker definitely gets lower than the straight VL modded one. Others, who have built proper size cabinets from scratch have reported huge performance improvements, particularly in bottom end.

    I'm pretty certain that all Mach speakers, including II and later, would benefit from larger cabinets. I have a couple threads on the Mach speakers, but one thing that I found curious and later confirmed was the similar sizes of the cabinets. If one uses a standard 4x8 sheet of Ply/MDF (or whatever) you maximize the use of wood keeping the dimensions the same. Less waste. However, that is NOT best practice in speaker building.

    Last, are you saying the DCM and 4000 were in the same room? Curios, did you try different placement for the 4000? Aren't the DCM a bit more placement friendly? Another plus, I'm finding applies to many speakers, is more volume with the DCM. It's down right astounding how much an improvement can be attained by having drivers in the correct size cabinet. I'm of course complimenting the design of the DCM, rather than down playing the 4000.

    I find it interesting when people mod RS speakers and arrive at very respectable speakers. Makes you wonder why RS didn't go that little extra step. Just seems the cost would have been almost meaningless, but we are talking bean counters first, technology second, eh?
  12. janikphoto

    janikphoto Addicted Member

    I had some pyle mids in my truck in the early 1990's, and yes... they are darn good. They are great for good old fashioned rock 'n roll.
  13. amante

    amante Member

    janikphoto, you are right about those Pyle mids…sleepers they are!

    Copa1934, so even after the internal hole drilling from Vlady you then removed the rear upper backing of a Mach One and realized more improvement? Wow, never thought of that. You will have to let me/us know how that looks here or on that terribly long Mach One thread! Probably the last step before simply building a whole larger box…but I might be up for this.

    The DCM Time Windows 1 are everything you said and what others have said…frickin' indestructible and audiophile! I have driven them with loud Classical and my son now drives them hard with his current metal rock. They just don't care and sound great…although a little rolled off at the top. MichiganPat knows what I'm talking about. They act like upper AR9 models in that they absorb electricity however DCMs don't require a heavy amp. I've seen their prices slowly rise on ePay.

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