New project will finally start, best bass from Seas standard line?

[Karoliina]

Hi,

The previous loudspeaker project is still under crossover tweaking, but I am planning to start the next project in the mean time as well.

I have decided that I will choose the drivers for this prototype
from Seas standard line range which fits into my current budget
and I have also concluded that they will serve the purpose
in this project well.

Requirements:
- High efficiency
- Good transient response

Design:
- Will be most likely active
- Three way with possibly horns or at least waveguides
- I may try multiple different designs (waveguides, horns
and cardioid enclosures)

Anyway, tweeter and midrange is already chosen:
Seas 25TAC/GW tweeter
Seas MCA15RCY midrange (execptional Fs/Qts ratio for a Seas driver)

The lowest bass will be produced with subwoofer. I am planning
to get multiple Peerless XLS 12 units or a single Tumult. I haven't
chosen the driver for the new sub yet.

These will be home theater LCR speakers. I would like the
bass to go down to 50-60 Hz. (No need to go lower because
of the sub).

Frequency response is no problem since active equalization
will be used.

I don't want to have bass reflex tuning in the enclosure because
I feel that it degrades transients. This time I will not go for
bass horn or transmission line. I am planning sealed box,
possibly unoptimal sealed box where the emphasis is not
the optimum acoustic equalization extension to low frequencies
but the optimum transient response.

Anyway, I have so far wondered which of these would be
the best solution:
H 245 CA25RE4X 25 cm 188,60 24 0,23 30,0-40,0 litres QC 30-1500 Coated paper -
H 372 CA25RE4X/DC 25 cm 187,90 35 0,31 40,0-50,0 litres CC 30-1500 Coated paper -
H 368 CA25FEY 25 cm 150,70 31 0,28 40,0-50,0 litres QC 30-3000 Coated paper

Another option is to use Peerless XLS 10 or XLS 12 as the bass driver for these speakers already without getting the bass from Seas line after all.

I will place the driver order today or tomorrow at the latest.
Please be quick with your answers.

Final requirement: Efficiency higher than 90 dB /1W.
Please don't suggest me anything from Excel line because
that is out of the budget and don't meet the efficiency requirement.

The reason for this new project is my goal of designing the ultimate home theater speakers that can be used even in the bigger rooms and that can deliver the maximum impact of the most dynamic passages of action movies without sacrificing the accuracy and with low distortion.

And please don't suggest compression drivers, they will be used
in the next project after this project.

Waiting for your answers,
Karoliina

[mgoedeke]

A high EBP doesn't mean that a driver' is suitable for Horn loading. According to Tom Danley the Motor strength BL/sqrt(Re) is more meaningful and my simulations with horns coincide with that.

P.Audio have two very interresting drivers coming up for mid-horns (MD-720 and the upcoming neo version) suitable for loading from 150Hz with power response up to almost 1k and response usable to 2k if you employ a phase plug.

These should also make for some very good direct radiating mid drivers, even if they are 6". Have a look at the enclosed data

[Edit: added file]

[Karoliina]

Hi,

In fact looks quite promising. Where I could order them?
I don't know any Finnish resellers for P.Audio.

Can you tell me more about employing the phase plug?
In other words, do you mean that I would remove the
dust cap and replace it with a phase plug? Can you tell
me more about it? I am particularly interested in this
because Avant Garde Solo looks rather interesting design
and I have sometimes wondered if I could do a similar speaker
but I have quite much abandoned the idea because I have
thought that it is too hard to a) replace the dust cap with
a phase plug and b) to find a compression driver that can
be fitted inside the phase plug.

Best Wishes,
Karoliina

[mgoedeke]

I am refering to a phase plug of a horn that widens dispersion above the frequency whre the mouth becomes significant in terms of the wavelength, in the above case about 1kHz. A phase plug like that employed in most drivers is much too small. Look for the Limmer 6"/1" horn (LIM-042) at www.lsv-achenbach.de for some ideas. Click on Produkte/Online-Shop. You would have a hard time improving on that design, as it has extremely good dispersion and is loud even amongst PA speakers.

Martin

[Edit: Limmer model nr.]

[Bricolo]

High efficiency + SEAS


Good luck

[roy]

Hi Karoliina,

Best (not deepest) bass from Seas standard line, and 10" I assume? I would say L26RFX/P but it has lower sensivity than you want. Of the mentioned drivers H 368 CA25FEY is the best. If you can get the CA25REY it's even better. But it can be difficult though.

Interesting project you have there. I really liked your waveguides.

Roy