Boominator MINI (development thread)

Hello All

I am a complete noob here, I'm not well versed with speaker enclosure design, I'm not well versed in electronics but I am perfectly capable of sound engineering, soldering and I can recone speaker drivers, so I'm a noob in some ways but OK in others.....

I'm based in the UK, I want to build a boominator and stay true to the original design because Saturnus, quite obviously knows more about enclosure design and electronics than I.

However, P.Audio may be based in the UK and “Blue Arran” are their UK distributor but you cannot get the HP10W here......

I wrote to Blue Arran for advice on potential replacements and I really helpful guy called Jon Harriman sent this reply...... I thought that some of the readers of this forum would find it useful.........

“Thank you for your enquiry. Looking at the available info on the Boominator, the speaker selection doesn't actually seem to have been a particularly critical part of the design of the box - quoting from the original diyaudio thread, "I used 4 P.Audio HP10W woofers because they're cheap, sounds great, and not least because they had the perfect depth for magnet to magnet mounting". It looks less as if the box has been designed to work specifically on the back of a particular driver, and far more as if that driver has been chosen as a matter of convenience, and the lack of a wealth of other drivers listed on the website is more a case of low end-user feedback on the matter rather than other drivers being technically precluded.

The box has been tuned to 82Hz, and is functioning as a straightforward bass reflex enclosure, so realistically you will have successful results with any 10" driver of suitable size and power handling, with a resonant frequency lower than the tuning frequency of the box. P-Audio's SN-10MB, which is also listed as being suitable, has a mounting depth of 122mm, so I'll take that as the maximum depth (both the original choice and the Eminence S2010 have a depth of 109mm).

Regarding the loudspeaker options listed on the Boominator site - we can't, unfortunately, get hold of the Goldwood driver at all, I believe this is solely available in the US market.

HP-10W - P-Audio now only make this driver to order. Whilst we are P-Audio's UK importer and distributor, we would need an undertaking for an order of 12 off drivers, and would be on an lead time of approximately six months from point of order.

SN-10MB Series II - This is still available from P-Audio, but unfortunately we don't have any in stock at the moment, so again we'd be looking at quite an extensive lead time (probably 3-4 months absolute best).

Eminence Basslite S2010 - Again, not in stock on the shelf, but available on a shorter lead time than the P-Audio options, usually around 2 weeks or so.

Recommended options:

http://www.bluearan.co.uk/index.php?id=PAUE10200S - http://www.bluearan.co.uk/index.php?id=PAUE10200S P-Audio’s E10-200S performs extremely well – resonant frequency of 73Hz, around the same as the SN-10MB. The quoted sensitivity figure of 93dB is actually quite misleading, it performs significantly better than that, and will actually deliver 100dB-plus across almost everything from 100Hz right up to 5kHz. Checking out the spec sheet, the E10-200S significantly out-performs the SN-10MB in many respects, with the exception of the Xmax being a little lower and the fact that it’s a heavier driver. Depth 109mm. Available from stock.

http://www.bluearan.co.uk/index.php?id=EMIDEL10A - http://www.bluearan.co.uk/index.php?id=EMIDEL10A Eminence Delta 10 – 350W RMS will also work , resonance 66Hz, 98.8dB/W. Depth 108mm, available from stock.

Incidentally, for the tweeters: Motorola sold their piezo production line over a decade ago, and production has since passed through several hands. Currently available in the same profile as the KSN1001A is this:

http://www.bluearan.co.uk/index.php?id=SKT900298 - http://www.bluearan.co.uk/index.php?id=SKT900298

I note that Saturnus also recommend use of P-Audio’s PHT-407N tweeter. The sound of this high frequency horn and driver is significantly more refined than you’ll be able to achieve from piezo drivers, and if budget will allow, it’s definitely worth looking at. One caveat, though – it will need a crossover, whereas the piezo driver will not. Here’s the PHT-407N:

http://www.bluearan.co.uk/index.php?id=PAUPHT407N - http://www.bluearan.co.uk/index.php?id=PAUPHT407N”

Obviously, this guy is at work and doesn’t have time to read all of the threads here, so I put him right about a couple of issues (ie, the drivers being an integral part of the box structure) and this was his reply back....

Fortunately, both of the drivers I’ve recommended are around the 108-109mm region, as (or at least so it would appear) per the HP-10W. Interesting claim regarding the idea of the magnets coupling – not sure how effective that would actually be in practice, particularly with the pole pieces in place. Incidentally, indoors or outdoors is largely irrelevant – although setting up near walls/corners can reflect sound which would otherwise be disappearing in an unproductive direction.

You’re absolutely right, the E10-200S is heavier than your original choice, actually by 1.4kg. Frankly, I’d say for the extra 5.6kg per box, it’s well worth it, you’re getting better power handling and significantly better sensitivity (as I say, ignore the quoted 93dB, it’s wildly misleading at best). Delta 10 actually a little heavier; decent enough driver, but I think you’ll get more mileage from the E10-200S.

Eminence Gamma 10 should work too, and are at a pretty keen price: http://www.bluearan.co.uk/index.php?id=EMIGAM10A - http://www.bluearan.co.uk/index.php?id=EMIGAM10A 

And Fane’s Sovereign 10-125 is another option, although a little shallower, so you may need to rebate the driver into the baffle to compensate: http://www.bluearan.co.uk/index.php?id=FANSOV10-125 - http://www.bluearan.co.uk/index.php?id=FANSOV10-125

There are a LOT more drivers to choose from, what I’ve put forward here is really the budget end of the market. Budgetary constraints are realistically likely to rule out both the Eminence S2010 and the SN-10MB – this is a knock-on effect from the  automotive industry using a lot of neodymium in motors for hybrid vehicles, which has largely priced it out of the market fro speaker magnets unfortunately.

Tweeters – piezos are actually remarkably efficient, and as they don’t need a crossover they make for a very straightforward solution. As cheap drivers which need no other fittings except arguably a resistor, they’re extremely hard to beat on the cost-front. On the other hand though, with a suitable crossover in place a tweeter won’t affect the resistance of your box overall – your biggest hassle will be finding an off-the-shelf crossover designed for a 4 ohm woofer and an 8-ohm tweeter. Building your own is a lot less difficult than some people will make out, but of course this may well be an avenue you’re not keen to explore. Tonally, you’ll have a far nicer box with the PHT-407N, but whether it’s worth the expenditure and effort is entirely your call.”

So, this has given me plenty to consider, I still have to go for the budget option because a boominator lite or a signature boominator is going to be too pricy for me (Looking at £700+).  I may have to swallow the extra weight and try the P.Audio E10-200S. It may be well be worth a punt........

Comments more than welcome