Single sheet TH challenge

Have you given any thought towards allowing the ability for complex inductance effects to be included into HR modeling?

Hi Josh,

Some time ago I looked at the possibility of allowing for lossy inductors, but decided that it would probably just complicate things unnecessarily.

How is complex inductance specified on the data sheets supplied by the driver manufacturers?

Sometimes it can be quite difficult just finding a value for the standard Le parameter as required by Hornresp :).

Kind regards,

David
 
Hi Josh,

Some time ago I looked at the possibility of allowing for lossy inductors, but decided that it would probably just complicate things unnecessarily.

How is complex inductance specified on the data sheets supplied by the driver manufacturers?

Sometimes it can be quite difficult just finding a value for the standard Le parameter as required by Hornresp :).

Kind regards,

David

Most manufacturers will not provide this info. The problem is that many bass drivers cannot be accurately modeled without complex inductance as it can affects response shape, sensitivity, efficiency and cone excursion. If you do happen to measure or get provided the information few of the widely used simulation softwares can make use of it.

I wondered if you had looked into adding it. I can understand the reluctance to bother with it when the amount of data available to take advantage of it is scant. Just throwing it out there as a possible future upgrade in capability. Thanks for your all your efforts.
 
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Hey guys!

I was wondering if I could get some guidance. I have a pair of DIY TP-1 corner horns using Lowther DX4 drivers. I want to add stereo subs to these for a bit of punch. The TP-1 seem to start rolling off at about 40Hz? I'd like to do a TH design that I could fit between one side and the wall, which would restrict the dimensions to 1024mm high and 566mm deep. Width is is up in the air, but I think I'd like to try a 8" or less driver.

So, first question. What driver? Second, any existing design that you might recommend?
 
Neo peaked in June of 2011 and the price has dropped a lot, 50% since November.
Although neodymium has dropped, dysprosium, used to make neodymium magnets heat proof has gone way up in price, making the net cost for neo speaker magnets static.

Without dysprosium, the neo would loose it's magnetic strength at high drive (heat) levels.

Dysprosium is still going up, and is very difficult to extract.

We are not going to see cheap neo for some time (if ever), JBL has stopped making the neo SRX line and has replaced it with a ceramic magnet series.

Art
 
P.Audio have even put up some marketing blurb on their website:

"Got the Neodymium Blues?
We’ve got the Cure

No doubt about it, Neodymium is a great material for compression driver magnet structures. Low weight, extremely high energy and superior bandwidth all combine to make Neodymium based permanent magnets the material of choice. Unfortunately, the price of Neodymium has increased to the point where it’s even difficult to purchase.

At P Audio we saw this trend coming and invested many hours in optimized ferrite designs. We’ve even added alternate and lighter weight material in sections of the magnetic circuit where very little magnetic energy was focused."

blah....
 
Is marine ply worth the cost of upgrade?

Intelligent use of bracing and construction methods are worth far more than a plywood with waterproof glue. That is the claim to fame of Marine grade plywood versus void free Baltic birch plywood.

But I have built many a cabinet out of poplar, and even OSB and they all work well when applied intelligently.
 
PD154 suitability?

Hi all,
New here, so I have way less experience in the design and build side of things but have been looking for a project to use a pair of Precision Devices PD154 drivers that are awaiting reconing...

Does anyone have an opinion on the suitability of these drivers for the single sheet 15 box?

Here are the T/S parameters:

Fs 39Hz
Re 6.2 ohms
Qts 0.205
Qms 4.32
Qes 0.216
Vas 149 litres
Mms 125 grams
Sd 890 cm^2
Cms 133uM/N
Bl 29.65 T/m
Xmax 7.7mm
Vd 0.658 litres
Ref efficiency 3.94%

Thanks in advance....
Steven.