Harlech clone possibilities

[trumper]

Planning a first build and I am looking at the microtower design. Could it be modified to a Harlech clone using the "twin pipe quarterwave" baffle as shown on the Castle website?
Would there be any benifit to this?
I have MJK's worksheets and am trying to find the one which would best model it.

[Nanook]

I think so, but why not try the micro-towers scaled up? That would make sense to me. Oops, the microTowers with the base modification is quite similar. Now if the μTowers use a tapered TL (I have to look at P10's box library), then I think that this could be interesting. So with the drivers mounted at different points along the TL, then the drivers would be tuned to 2 different frequencies, and so could smooth out the response of the drivers (methinks, help Dave/chris).

I have always liked the Castles (I own old Durham 900s which I love) and thought the Howard(S1), etc were quite good, and you don't need speaker stands.

[chrisb]

Originally Posted by Nanook

I think so, but why not try the micro-towers scaled up? That would make sense to me. Oops, the microTowers with the base modification is quite similar. Now if the μTowers use a tapered TL (I have to look at P10's box library), then I think that this could be interesting.

- No, they're a basic straight pipe MLTL - the originals were designed to fit a particular form factor, but of course Dave may have conducted at least thought experiments on expanding the concept to larger than approx 4" drivers. Indeed, I may very well have seen such drawings - it's kinda hard to remember, much less build 10% of them.

IINM, Greg Monfort or Jim Griffin(?) designed a dual / offset MLTL bipole, and not doubt there's something like the above idea out there.

[Nanook]

no dims, no calculations...

[chrisb]

Originally Posted by Nanook

no dims, no calculations...

or Bert Doppenberg's cute little dual driver pipe - the first FR enclosure that got my juices going - originally designed for an EOM version of Fostex FE103 . "We" must have built a dozen(?) pair with old Foster variants, RS1197 plus some fun with cheap tweeters



BD-Pipes


In some ways, not unlike the Castle version of Microtower in use today

[trumper]

That is along the lines of what I was thinking. I wanted to scale down the Harlech to something like the size of the micro tower for 4" drivers. Here is a pic from the Castle website of their twin pipe baffle and a pic of my attempt to modify the microtower. My room limitations would better fit a driver on the top and front I think.

[GM]

The key to the Castle's bass performance is its base-plate loading which can be approximated in a sim by progressively reducing the vent area to mimic reducing the air gap between them, though never having had any simming software to maybe find some rule-of-thumb you will have to find the best overall performing air gap empirically.

Personally, I prefer this type of vent damping whether floor, base-plate or even wall or ceiling loaded, but some don't like it, so Caveat Emptor.

Note too that the driver's acoustic center is more in line with my preference for a TQWT [ML-horn], i.e. below MJK's recommended path-length/2, so use his software, HornResp or similar to fine tune path-length Vs driver/floor distance.

GM

[chrisb]

Originally Posted by trumper

That is along the lines of what I was thinking. I wanted to scale down the Harlech to something like the size of the micro tower for 4" drivers. Here is a pic from the Castle website of their twin pipe baffle and a pic of my attempt to modify the microtower. My room limitations would better fit a driver on the top and front I think.

Note that we built 2 versions of the "Planet10" microtower - a conventional bipole directly analogous to the original EPI Model 1, and what we nicknamed the Castle - i.e. with one driver up-firing, no filters. Certainly not entirely scientifically, we installed different driver models in the two - Mark Audio CHR70 and EL70, with appropriate adjustments to vent tuning. I've been living with the EL70/castles for over a year now, and highly recommend the configuration.

[trumper]

OK. I have pulled the trigger and ordered the EL70 microtower speaker package from CSS. Having run a number of sims in the MJK spreadsheets I think i am best off to just do the castle microtower. Next question - would tilting the top 10° or so forward offer any benifits (apart from people not putting drinks on it)?