Dilema

Those with exceptional memories might remember me posting nearly a couple of weeks, ago asking about replacement diaphragms for the paudio BM 450 comp drivers. As a result of that post, Tony (AJW) contacted me to ask if I would like to try a new 1” BMS comp driver. Why not all I had to lose was the cost of posting it back if I didn't like it. It turned out that I didn't even have that to lose as Tony doesn't live that far away from me and dropped the drive unit off last Monday.

I managed to try it out today and my initial impression is that it is a really nice drive unit. I've taken some measurements and pictures of the test session and will try and put them on my web site as soon as I can.

You will have to contact Tony for an exact price, but for the size and price it would be difficult to beat.

So the question now is do I take the driver out and put the B&C 250 back or do I stump up the cash and get another of the BMS drive units and should I even bother with the paudios?

Just choose the best driver, If you can avoid it, don't think about the cost difference. Only choose the best.

Tony (ASS)

The cabinet that I'll be using them in is a stage monitor with a Fane Studio 12b. The high horn is a B&C ME10 and to be honest I think that the diminutive sound predominates the lower end of its frequency range. Both devices would, I think, benefit from a better horn. The cabinet was designed to a given size rather than performance so that is what fits.

Additionally the two main venues that I use this in require some funky eq to stop a low-mid resonance caused by the snare being picked up by the vocal mics. In this application the quality of both drivers is wasted. This was where I came in. I want to build some small cabinets for acoustic gigs and was thinking of matching the 250s with some decent 8” drive units (maybe B&C) and fixing the paudios to go back in the monitors.

What I might end up doing is getting another BMS from the other Tony (AJW) to put in the monitors until I can get some replacement diaphragms for the 450s and then use the BMSs with some Precision Devices 8” units that I have. That way I will get to use them in real conditions when they are being given a more thorough workout than a brief listen in the back garden.

As I said, when I get some time I'll put a more detailed review on my web site with some response plots.

One thing I would say about monitors, and that it is very important to get them as flat as possible. Monitors by nature when they are facing a mic are vunerable but a flat response to start with gives you a head start. If your cabs are passive the x/o should be interfered with so that you have perfect balance between your speaker and the horn.

I built a wee 8" coaxial mini monitor a while ago, works well but has annoying peak aroud 600hz. What might i do about that? never gets run thru a graphic at the gig's it's used for
passive notch filter?

I used some of the ME10 horns briefly but I found they were too small to load the compression drivers properly below about 3kHz. They probably are causing some of the issues when trying to get the boxes sounding right.

I think putting the little BMS drivers with some 8's would be a good plan. Ideally you need some boxes for the Fanes and the DE250's on a larger horn.

I would go with not using the P-Audios.

Chris, one of the main reasons I keep bangin on about the little BMS units is that I still cannot get my head around the standard of performance and indeed the output for the price.

I use then in my small pair of twin 10" mid tops that get used for all types of P.A.duty from heavy metal bands in small venues to general disco's for up to 200 people. The twin 10" drivers are fed from a Crown XTI4000 so they see 1200w although the amp is not allowed to clip.
The comps are run on a XTI1000 so can get 275w. The comps are crossed at 2.08K 24db/oct. The comps have no problems at all in keeping up in fact I have NEVER even seen the -20db light come on in the comp amp!!!
I have just used them on an install using them with some twin 8" i.e. MTM arrangement and they really are about as good as I have heard * regardless of price.

* P.A. wise

Tony

While the advice is appreciated, please stop. Perhaps in hindsight the title dilemma was wrong. The dilemma was more like being a kid in a toy shop rather than not knowing what I am doing.

After my post in the previous thread, about the paudios, Tony was kind enough to let me try out the little BMS driver. He was obviously confident that I would like them and I do, which is why I posted. If they are as rugged as says then they are a great drive unit and deserve consideration if you are after a 1” comp driver. I think that I'll probably be able to pry open my wallet to try a couple.

Unfortunately, in these environmentally aware days, I still have the paudio magnets which would be a waste to dump and are a bit big to stick on the fridge.

I'll let you all know when I have put the pictures, plots and fuller review on my web site.

p.s. Tony, just seen your pm. I'll get back in touch soon.

I've managed to put up the pictures and frequency plots that I made. The link is:

<a href=" www.burton-manor.co.uk/Audio/lynn_and_st..._misc_audio_page.htm " target="_blank"> www.burton-manor.co.uk/Audio/lynn_and_st..._misc_audio_page.htm
</A>
Just scroll down the page you can't miss it.

Steve,

Hi Steve interesting to see your measurements on the driver. I am quite surprised to see how poorly the horn performs, I can only assume that it is because it is optimized for dispersion. Could this be a function of your measurement procedure? Have you done a measurement with the speaker on top of a 2m pole with the mic on axis?

On the two horns that I have used with the driver both show that it is capable of output well below the 1.9K recommended X-Over point and that when eq'd for a c.d. horn it is still singing its little head off at 20K.

With regards the power handling do not forget that on standard pop music etc. the frequency band above 2k only gets about 10% of the total power input. That would mean that for a 300w system the 2k plus frequencies would get 30w however as you have implied that it would need 10db of attenuation so only 3w would be needed by the comp driver!!

Tony

Edited by: AJW