BillFitzmaurice.info

Hi everyone, I know it's been a while, hope this finds you all well. This is a question for Bill, or anyone that feels they have sufficient knowledge. I'm looking at options for a horn design that will cover the band of 60 to 200hz really well, T48 possibly ? I know the upper sub bass range would sound great but how would it sound in the upper mid bass, any good ? Recommended driver for 60hz and up, LF or HO ?

Or perhaps dual driver T39 ?

G'day Alan,
Your time was before my time so hello and welcome back

Is this to go with your T36's/DR300's?
What's the application?

The drivers have may changed a little over the last couple of years. So, for either cab, and latest recommended drivers, it might be great to get plan updates from Bill if you have old plans.

I notice the premium loaded T39 (lab 12 or 3012lf) has a generally rising response from 60Hz to 200Hz, ranging from 100dB at 60Hz 1 watt/metre to 110dB @ 200Hz.
This seems to be the strongest area of output for the T39.

The T48 is similar, rising, but not as much, arguably somewhat flatter, slightly higher than the T39 output wise at 60Hz but much the same at 200Hz.
Recommended 15's for the T48 are the Lab 15 and 3015lf.
Same same in regard to strongest region.

Hope your sitting on your seat when you look up RRP for these drivers here in Oz now.

I'm sure either would sound fine, but localised with the content above 100Hz.

I noticed you ran the DR300's as kick bins, and just wondered of you had phase issues with that?
Nothing's changed much, it's still not advised to run different horns together to avoid phase issues...

Hi Grant, yes the dr300s worked exceptionally well down to 80hz but I've sold them to a friend wo uses then with t36 that they built. The application is edm, I miss having the dedicated Lo mid that I had with the dr300 and this time I want to go down to 60 hz, I have other subs that I'm happy with that do from 30 to 60hz. Thanks for your recommendations.

No worries Alan,
Didn't really answer your question, but at least you have some idea of what you're looking at...

Let us know how it goes...

No, thank you. Also, no phase issues that I was aware of, I used delays, steep xovers and checked for phase coherence at the xover point. I would be running them over different pass bands not the same frequencies.

I like how flat the T48 is from 60hz.

I feel like the T48 is too big of a solution for just Sixty to 200. what is the current foot print of your subs?

I have 8 lab subs 90" x 90" x 45" deep.

I think 2 per side would probably be enough so long as they can do the upper frequencies well ?

I had a feeling it was lab subs. I believe I still have a picture of one of your rigs haha.

Every Rig I've heard running labs seems quite solid to 80.

then again there is this picture as well (equivalent volume of t48s, vs a single lab sub)

Notice the t48 is actually better than the lab below 35hz, and the lab exhibits a peak right at 35. this is due to rear chamber volume. the labsubs actually have VERY small rear chambers, which help keep overall horn volume lower, and control excursion (the lab has a loose suspension). the larger rear chamber in the t48 helps LF extension below horn tuning, although distortion is rampant below that point (in both the lab, and the T48). The Labsub could actually benefit from greater rear chamber volume, as most of the failures I've heard of are due to thermal failure, as people are having trouble pushing the 13mm xmax of the lab itself, but the small rear chambers are basically easy bake ovens after 8 hours hard at 50v (or 100v in series) .

there's also this graph, which shows 4 t48s, vs 4 labsubs (half the cab volume).



this would be 4 t48s per side (over 4 labsubs). As you can see, a stack of 4 labs covers the upper freq ranges just as well as 4 t48s per side (twice as many as you thought you would need).

If you are set on needing 70 to 200, I think a different horn design might be needed, or perhaps a direct radiator kickbin.

IMO labs sound best run to around 60hz only. You may be right, the T48, I'm sure is a great sub by itself but may not be ideal for what I'm looking for, which to be honest is basically something that does this > http://www.funktion-one.com/products/f215-mk2/

sine143 wrote:kickbin

Don't think this is the realm of a BFM design, unfortunately... I remember a lot of kerfuffle about the term and purpose many moons ago
There are a few good options out there, especialy a couple specifically designed to sit above LABs, but probably best to be fair and not discuss them here

USB's are designed to cover the kick range above the Labs. They also fit nicely over 2 of them.
These BPH238 loaded with PD.154 drivers are one of the best sounding kicks i ever heared.

Thanks, I've looked at the uSb design before but would prefer not to use not to use 18" drivers on a short horn and it doesn't go quite high enough, the other design looks good but doesn't go quite low enough :/ Thanks everyone for your suggestions, just exploring options.