MB 115-H

Art. No. 5926

Characteristics - Sound Properties

The MB 115/H professional musician's speaker is a compact, excellent value for money vented cabinet. It is equipped with the BGS 40 8 Ohm woofer and the HTH 8.7 8 Ohm mid- to high-range horn. A 2-way combination has the invaluable advantage of simplicity. However, combining a 15" woofer with a tweeter is not completely without its problems, since the cone of the woofer must also produce resonance-free and distortion-free sound in the mid-range. The tweeter, for its part, has to be distortion-free at relatively low frequencies and, at the same time, have good power handling capabilities. We decided on a cut-off frequency of 3000 Hz - a level both speaker drivers can cope with effortlessly.

The rated power output of the speaker is 200 watts. This rating is determined in accordance with the DIN standards using a permanent noise signal. This value is, however, far removed from practice, since music consists of many different impulses and surges. The effective value, that also tells us something about the heating-up of the voice coil, is much lower with music. We have successfully tested the MB 115/H with a professional-quality amplifier up to the clipping limit, so we are safe in saying it has a music rating of 500 watts. At this level, peak outputs of 120 dB are achieved at a distance of one metre.

MB 115/H is part of the combinations:
PA Combination B

Frequency response

Construction

If the speakers are likely to be transported frequently, it is advisable to make the cabinets out of multilayer board with a thickness of just 15 mm. This will keep the speakers very light and yet sturdy in case they are knocked in use. The final surface could then be either non-scratching 2-component paint or even carpet. Corner reinforcers are useful for stacking or just to protect the corners. In the drawing, we have shown the ST 77 terminals. The more professional solution, however, would be a terminal plate with two XLR or Speakon sockets. This way the signals can be passed through to other speakers. Of course, for transport purposes, carrying handles in the sides and a flange in the base for a stand are essential extras. The front baffle is moved 30 mm back, in order to protect the driver. Additionally, a grille can also be fitted to the woofer (the grille and other accessories mentioned are all available in musician's shops).

If you do not have a circle cutter for the port and the jig-saw solution does not provide the required quality of openings, it is also possible to use a BR 14.70 tube with a length of just 15 mm. In this way, you just need the tube flange to give it a finished appearance.

Inner damping

The damping simply uses four mats of damping material placed in the cabinet behind the woofer.

Crossover

Sketch