Rolls MB15b Promatch 2-Way Stereo Converter

The ROLLS MB15b PROMATCH works well.The product is built well.The Power plug going into the Rolls Promatch connects well, holds in there tight.- - - - - - - -I'm using this with RCA 'LFE .1' connection (From preamp/receiver) - to the promatch - to - Balanced connection on sub.- - - - - - - -Besides that,- My setup personally, I had issue getting my sub to turn on properly or stay on at lower volume or bass amount.- I'm sure it's not the sub, but The solution for me is to Turn the level on the sub itself down a bit (+6db to 0db or a bit lower(MONOLITH M-10 V2 SUB)) and adjust the level on the ROLLS MB15b accordingly to what you need to make it work properly.It's Something to do with the auto on/off feature that I want / need to use.- At higher volume there is no issues seeing it's a lot more signal, so I Could essentially go ' +6dB ' on the sub level itself, and whatever level on the ROLLS MB15b, but for me in this room it's not about turning it up to 11 all the time, I want Balance in my room with the Bass and the speakers + the room. .. & be able to have audio at lower volume without losing the signal to my sub...I hope this info helps anyone having any issue or problem getting their sub to work with the ROLLS MB15b.** Additionally - I'm currently keeping the level on my ROLLS MB15b between 11 - 1 o'clock 'turn' .. depending on what I want at that time, and/or what I'm listening to, it's simple and works.** In my Current situation / setup I Don't think I will need or want to turn the level up a lot more, as it will be off balance with the setup/speakers.. And just be too much.Great Product! :)Good Luck with your setup.

This is being used in our computer audio 2.1 setup. (1) pair of wall mounted NHT Superzeros, (1) Denon AVR 1907 connected with optical to our computers output, (1) Rolls Promatch MB15B (been using it for a year or two already), (1) Crown XLS2000, (1) Infinity 1262W in a 4.6cu ft vented box we built tuned with an F3 approx 21hz.The Rolls Promatch doesnt appear to add any distortion or hiss or feedback and most importantly it solved our issue of low output. Sound quality of the Rolls Promatch? To my ears it does not alter the sound in anyway. No distortion, no hiss, no feedback. It is a well designed piece of gear.Using a Crown XLS2000 to power a single 12" Infinity Subwoofer in a 4.6cu ft vented box we made. Before the Rolls Promatch, I had to turn the Crown gain up all the way to get substandard output from the subwoofer. After reading recommendations that said to get one of these... I ordered one. Let me tell you something, this Rolls Promatch brought our subwoofer to life!!!! Connected an RCA from the Subwoofer preout on the Denon AVR 1907 to the input on the Rolls Promatch. Connected an XLR cable from the Rolls to the Crown XLS input. BOOOM!! Now we keep the Crown gain at about 2 oclock. Sometimes we have to turn the Rolls Promatch down because the subwoofers output overwhelms the audio coming from the pair of NHT Superzeros.If you are mixing consumer audio receivers with pro audio amplifiers you should invest in one of these. Even the newer pro amps that claim to have a switch, to switch between pro audio or consumer input voltage, dont work as well from the reviews I read.You have a regular home audio/video receiver and you are using a pro audio amplifier? Get one of these if you want to use that power you paid for, otherwise the amp is barely putting out any watts because the input signal to the amp is too low.Side note, if you are like me and you have a 2000 watt amplifier connected to a $60 subwoofer that only handles 300ish watts, dont turn it up too loud playing extended bass notes because the voice coil will start to smoke. I was a car audio bass competitor 20 years ago. I have just a little experience with overheating voice coils (playing extended bass notes at the transfer function of the vehicle +10hz after loaded with pressure, for the SPL meter light tree :) I did hit 154.4 db though with 1400ish watts RMS with (2) Crossfire entry level 15"s in a 10cu ft vented box (play more than a few seconds and they would blow).

Got my MB15b in the other day. Opened the amazon box to find the device, power cable, and a small information pamphlet just sitting in the box with my other items. They weren’t packaged in any sort of way, and one of the small rubber feet was missing.Aside from the terrible packaging (or lack of) I really like the product. I have my Numark Mixtrack Platinum controller hooked up via RCA, and use the xlr output to send signal to my Cerwin Vega CVE 18 and CVE12 powered speakers. Works great. Rca to xlr cables worked well but I got a lot of signal interference. That went away as soon as I switched to this. Wish I had a power switch and a ground lift, but for the price it’s great.

I use this for two applications. I have a pair of powered DJ speakers and a powered sub that all use XLR connections. Unfortunately, my DJ controller only has RCA outputs. For several months, I have them connected thru XLR to RCA cables. Once I connected the Rolls Promatch, there was a big jump on volume! Suddenly I have more headroom. After a few hours of playing, I decided to try it on a second application. This time a pair of powered studio monitors (XLR) and a home audio subwoofer (RCA) connected to a laptop via a cheap USB interface (RCA) using "Y" connectors. Again, after adding the Promatch to the signal flow, there was an increase in volume even if the level knob is in the 12 o'clock position. I think this is the default "0" position. If you turn it past 3 o'clock, you will hear distortion or clipping! So far, I have used only Channel 2 for both applications. And no more "Y" connections since it has both XLR and RCA outs on the same channel. A couple of things that I wished it had were a dedicated "on/off" switch and possibly move the inputs from the front to the sides so no cables to hinder the operation of the level knobs. This little contraption has saved me from purchasing a very expensive DJ controller with XLR outs and matching powered sub for my monitors.