Some advices for a 2 way, horn and 12" ...

[Biscu]

Hello,
I am not so experienced to diy, but starting a new project for a 2 way loudspeaker ... I already have the 18Sound XT1086 and I cant decide what driver to choose from: 18Sound ND1030, B&C DE250 or Beyma CD10ND !?

The bass driver I already have is a Celestion TF1225 and also I have the crossovers from Beyma model FD250.

Due to some room space and WAF restriction the bass driver box will be arround 45 litres volume, with a bass-reflex tube from Monacor model BR-100HP (93mm diameter and 140mm lenght).

Please advice me what driver (from the mentioned ones or similar price) will work better with my horn 18Sound XT1086.

And also I would need some opinions regarding the proposed bass enclosure ... Will work?

I am doing these loudspeakers for home hi-fi, 80% heavy-metal music, I don't like very low bass, I love drums to be present, clear and low but not boomy. My room seems to have a problem arround 60Hz

Thank you for your time!

 

[LineSource]

STUDY: 18Sound HD1050 or HD1040 1" compression drivers with a LR4/LR4 crossover at 1600Hz to your TF1225 in a 100l ported F3=80Hz box. Port Dia = 10 cm Length = 31 cm
===============

If you search the 18Sound website you will find a couple diy-designs based upon the XT1086 horn. Although the parts used may be above your price goals, the designs are good examples to study.

Your Celestion TF1225 has an Fs=60Hz and Qts=0.5 and therefore cannot produce bass under ~80Hz even in a large ported box. If you place the speaker near walls/corners you will achieve some room gain, but not deep bass. The TF1225 is a midbass and not a woofer.

For even "acceptable" sound, you will need to design a custom crossover. It is doubtful that the 2Khz Beyma model FD250 will work with your selected components. A LR4/LR4 1600Hz crossover offers the best compromise for TF1225 polar match to the XT1086 horn.

There are a few threads on the XT1086 horn and the general observations from the datasheet data are:
1) XT1086 favors a 1600Hz or higher crossover
2) 1600Hz crossover with 80-degree polar pattern is a "strain" for most 12" midbass, and a "good pattern match" for many 10" midbass
3) XT1086 has a 27-degree mouth, and this matches 18Sound 1" compression drivers.
4) 18Sound compression drivers using their 44mm diameter diaphragms best support a 1600Hz crossover
5) modest cost Fe-magnet 18Sound 44mm diaphragm drivers include:
HD1050 Titanium dome over PEN suspension (Ti often delivers detailed highs)
HD1040 Treated polyethylene diaphragm (Plastic often delivers smooth highs)
============

UniBox sim of TF1225 ported:
"Vented Box, Vb = 100 l
1x Celestion"
"Peak Cone Excursion
1x Celestion
Vented Box, Vb = 100 l"
"Port Air Speed
1x Celestion
Vented Box, Vb = 100 l"
F3 = 083 Hz Fb = 025 Hz
Response peak = 000 dB
Qa = 80 Ql = 15 Qp = 80
Port Dia = 10 cm Length = 31 cm

 

[Biscu]

Sry for my absence ... but still alive!

Thank you very much for your time and advices LineSource!

Well, due to various restrictions, the volume of the mid-bass speaker has to be 60 litres. I already have a test enclosure (60 litres volume) and I tested the Celestion TF1225 ... HUGE disappoitment! No bass, no drums kick ...

So, the question is what kind/model/brand of 12" speaker should i choose for a vented 60 litres enclosure, to have real good drums sound with speed, presence and kick?

Should I choose a 12" bass with long excursion? with low Fs? with Qts ...?

I don't know what to do. But I find hard to believe I can't get from a 12 inch mid-bass driver some real drums sound!?

 

[Biscu]

Regarding my question about what 12 inch driver to use in a 60 litres vented enclosure (for a 2 way configuration with B&C DE250 and XT1086)

I can buy at good prices (reseller price) speakers from local Beyma distributor. So I was looking at SM-212 or SM-112/N, but when simulated with WinISD the response curves look similar with the Celestion TF1225 that disappointed me as bass response.

Looking at mentioned Beyma's speaker parameters they are really different from TF1225's (quite different Qts, very different Xmas and Vas ...) ... maybe I do not use in the right way the WinISD or I wrongly consider the small differences on the graph, maybe in real world sound those small graph differences will be relevant to my ear!?

Is anyone builded a 2 way with Beyma SM-212 or SM-112/N to share some opinions? Will be a real change, in bass, moving from Celestion TF1225 to Beyma SM-212 (or SM-112/N)

Thank you!

 

[burgunder]

Take a look at Beyma 12B100/R it will give -3 dB at 50 Hz in a 45l box.

 

[Biscu]

Thanks for ideea, but cant find this model on official Beyma web-page ... and I live far away from US, so not many options in my area.

But, should I look for similar specs drivers? Also my buget per driver is maximum 150 USD.

Another ideea might be to build the speaker with 2 drivers of 12" !? If I am not wrong this will compensate the bass response (not in depth , not interested anyway) and increase the total SPL for low freq ... am I wrong?

The problem is that I have to increase the volume of enclosure for 2 12" drivers

 

[LineSource]

Maybe.....3-way.....put the Celestion TF1225 12" midbass that you already own in a small sealed cabinet with the XT1086 and B&C DE250 . A sealed alignment will product tight transient midrange sound.

Add a woofer. Simulate 12BR70 or 15" woofer like the SM115/K for a ported cabinet.

The physics allows only two of these three: deep bass; small volume; low power.
Pro Beyma drivers favor low power, so low bass requires a very large box, and small boxes produce very little deep bass.

You could use "home audio" low efficiency 12" woofers in your modest size cabinet, and (with enough watts) get deep bass.
If you had electronic DSP compensation and a large amp, you could get deep bass from many different speakers in your box.

 

[Biscu]

I also start "cooking" an ideea like yours (with DSP) because my amp is Yamaha Aventage A2040 and has a fabulous Parametric EQ for each channel!

So, I will connect directly (without any crossover) the 12" bass driver to a surround back channel and the DE250 to the front channel (obvious both right / or left), also taking care to set audio listening to stereo all channels, to get the same signals both front and surround channels.

Than I can decrease about 10-12dB the DE250 channel to make it even with TF1225 SPL, and of course with Parametric EQ (for each channel!) I will cut -20dB the TF1225 over 1.6kHz and also cut -20dB the DE250 below 1.6kHz.

Does it makes sense what I said!?

For the TF1225 channel I can also increase up to 6dB the 100Hz area with various Q factors (0.4 to 8) ... in order to observe if kick bass (drums) come to what I want.

If all these works I can't see the need for a crossover! am I wrong?

Anyway I will share this experience after this weekend, maybe other people will be interested ...

And thank you again LineSource for finding time for a newbbie like me!

For those about to Rock we salute You!