Rat Shck Presidian 40-5053. Next Sonic Impact?

Picked up a pair yesterday just for fun. If they sound decent I'll pick up a 2nd pair and try stacking them. I'll report back when I play around with 'em a bit.

ALso - The floor models in the store simply say "Made in China" - nothing about assembled in USA, so I'm wondering if (per Eldartford's info) there are already different manufacturing lots to be aware of. I haven't opened my box yet, so don't know about those.

Hooked 'em up tonight. First impressions - they are undoubtedly excellent for the price, and may repond to some tweaking or EQ. They image very well, and do have an excellent coherence - which is of course to be expected since they're basically crossoverless. Without having done any measurements, I'd say they're a fair bit forward in the 3.5 k to 4.5k freq. range which is a little fatiguing. The highs are quite good though - these appear to be decent tweeters. The 65 hz low end stated in the specs is a bit of an exaggeration. I don't think they go much below 100 hz, and even there it's pretty rolled off. Plus, I'd say from 100 up to about 300hz is pretty sloppy - not audiophile quality.

My best guess is adding a small sub that could crossover at 120hz to 150hz might make these very affordable monitors for someone on a budget. A stack of 2 per side might help by inducing some coupling in the lower end and altering the effective EQ. I'd also experiment with leaving out one pair of tweeters from the mix. Placement in room corners would definitely help - which I'm not able to do in their current location.

I'll post again when I have time to experiment.

BTW - Mine state on the cabinets "ASSEMBLED IN CHINA" - so there are apparently different manufacturing lots out there (per Eldartford's version).

Just shoved an old t-shirt a few inches into each port and draped the rest over the top and then behind. Makes the upper lows and lower mids much more natural IMO without any effect on the freq. range as far as I can hear. So it's probably worth adding damping to the cabinet and filling the port tube with it. I doubt that the "port" had any audio design parameters involved in the first place.

I pretty much agree with Reubent. I haven't had any cheap speakers since my Spica TC-50's fifteen years ago, but the Presidians would certainly be no match for them with music.

An easy, affordable line array might be a legitimate idea though. or they might make decent cheap center channel speakers - you can by a pair with a friend and have one each for $20! They'd make a lot of sense in settings where you don't want or need a $400 pair but still want decent sound - like in a garage or workshop.

Thanks for the heads up - just bought them. I'd assume he'll post another set soon.

Now wondering if I should have waited for a litekeys upgrade2.0 - which would undoubtedly convert these into a line-array 3-way design with the addition of two more pairs of Presidians! :)

I'll post a follow up as soon as I finish them - my plan is to upgrade just one speaker first so that i can compare side by side.

I don't expect them to become world beaters, and it practically doubles the cost of the speakers which I was about to give to a friend in need, but I can't resist the fun of trying the mods.

If they can be used with our bedroom TV (where the baby has full access to pound and chew them) for a slightly better hearing of Live At Lincoln Center, Austin City Limits, etc., we'll be happy.

Well - I completed the upgrade on one of the Presidian speakers tonight and A/B tested against the still stock one. I used an old Marantz receiver for 2 reasons - it has the ability to run R & L speakers from one mono source AND it has excellent tone controls (Bass/Mid/High).

I need to do some more experimenting but here's what I've observed so far:

1. The upgrade kit is VERY reasonable for the amount of time Litekeys must put into it AND it is definitely an improvement over the stock. It took about 2 hours start to finish ( I soldered all new joints). You have to have fairly nimble hands to install the crossovers inside the cabinets.

2. Most of the improvement comes from the upper mids to the highs and it is not subtle - if you had to pick either the Litekeys version or the Stock version of the Presidian and not mod further, it's not a contest. The Litekeys is a big improvement.

3. That being said - the situation is more complex. By playing around with the tone controls on the receiver I was able to improve either Presidian considerably. On the first A/B comparison it became obvious that the stock Presidian is rather attenuated in the highs. The sound is muffled compared to the Litekeys speaker. However the Litekeys version is a bit lacking in the low end by comparison - which may simply mean, in a 2 way system, that the tweeter is a little too hot.

4. The original Rat Shack tweeter states 8 ohms on the back, while the upgrade (a Dayton ND20TA, cheap yet well-respected among DIY'ers for it's flat response) is nominally 6 ohms. However actual measurements from Dayton show it really runs about 5.5 through the meat of it's freq. range.

These relatively different tweeter efficiencies may explain a lot of the immediately noticeable audible difference between the stock and the litekeys Presidians.

I found that if I turned the Treble control nearly all the way up that the stock speaker improved considerably - possibly even bettering the Litekeys in the extreme highs and while maintaining the better bass at the same time. But it's hard to A/B that reliably because it involves flipping 3 nobs as simultaneously as possible. On the other hand, with the Litekeys speaker, turning the bass up a lot and boosting the mids a little yielded a substantial improvement to my ears.

5. So I don't feel that the Presidians are yet optimized. In order to sort this all out I feel I need to try a few things - in this order:

A. What if I just replace the stock tweeter with the Dayton in the 2nd (still stock) speaker and leave it untouched otherwise?

B. What if I add the Litekeys crossovers but keep the original tweeter?

C. What if I add, say, a 3 ohm resistor (probably about right) in line with the Dayton tweeter in the Litekeys version speaker to better balance the tweeter and woofer responses?

D. What if I add a 3 ohm resistor in line with the woofer in the stock speaker to attempt to better match the tweeter level?

I'll tell you what sounded better than either one at this point - stacking them on their sides and running both of them simultaneously with the balance a little higher on the Litekeys speaker. Their different tonalities balanced out very well and it really sounded pretty impressive. You could make a case for buying two pairs and running a baby "line array" like this - with one pair upgraded and the other stock. Not bad for about $125 total!

I'll report back here when I've tried as many of these as I can before my kills me....

This morning I A/B'ed the single Litekeys Presidian against a Dick Sequerra Metronome, which is admittedly a dated design - but cost about $800 for the pair new, and the Presidian was hands down the winner - with the one drawback being that softness in the lower mids. (Can't compare imaging obviously as I only have one Litekeys speaker right now.)

Also - Since I've hardly used the Presidians at all, even before the mod, and the Litekeys side has a brand new tweeter, I'm going to let them break in for a few days before trying my further ideas.

Hi again -

Sorry for the long delay, I've been very busy and somehow missed your last post. I've been running the stock and litekeys speakers in mono in my bedroom (not continuously) since my last post to really break them in. The litekeys has definitely improved - the bass level has come up a bit and the tweeter is a little more friendly. But for my ears, I still think adding some resistance on the tweeter will balance it out nicely.

I haven't the burning need to stuff the port on the litekeys version as I did with the stock. The addition of the crossover has cleaned up the woofer sloppiness quite a bit, but it's too hard to tell until I have two matching speakers running in stereo. I kind of wonder whether any analysis went into the design of the port at all - or did they just stick a random tube in the cabinet?
The rear of the cabinet has quite a bit of vibration which must be adding coloration, (as does the plastic grill frame, which is easier to eliminate) Even though there is a clever adjustable brace included in the kit, it can't really be engaged in a useful location inside the cabinet because the woofer takes up almost all of the front baffle. So adding stuffing may be useful to help damp some of that.

I'm hoping to finish up playing with these over the Xmas holidays, and I'll post my final results then.

Cheers, Chip