MTH 4654

Hi great design, are there any other (cheaper) drivers suitable?

Would a 15" work in in the design also? Possibly the eminence 3015lf?

Thanks in advance

Surprisingly, the 3015LF has a very good response in the MTH-4654, but you will have a limited power by X-max of 450 wattss, but it's the power of the speaker, so not a problem

a speaker in 38cm is too small for such a box, especially for reproducing the low end??

Finally, if the chef says it is good, the result will be equal to the gear ^ ^

look a t this horn: [Vous devez être inscrit et connecté pour voir ce lien]

Even if it has eight 18" per horn, it is incredibly big.

But don't forget, tapped horn aren't working like a traditional horn, so can't compare what can be done with a simple horn and a tapped horn.

Hi Marc, thanks for getting back to me, Would it be possible for you post up responce plots for the 3015lf driver?

PS is there any other drivers you would reccomend?

Big thanks

[Vous devez être inscrit et connecté pour voir cette image]
Eminence 3015LF
Blue : one cabinet 2.83 Volts 8 omhs 1w/1m
Red: : four cabinets, 1.41 Volts 2 ohms, 1w/1m

I haven't sim others drivers.

Thanks for the sim Marc,

Does the 3015lf driver exceed xmas at any frequencies?

Thanks again.

No excursion problem at full power (450 watts). You must cut at 30Hz (24dB/oct) or 32Hz (18dB/oct)

Hi Marc,

I'm very interested in the MTH-4654. I have a couple of questions.

What's the height of the box, is it 60cms? I can't see that on the PDF plan...
Have you tested tbe box?
What's a good 21" driver for the box? Can you show me a sim, or maybe post Horn repsonse details so I can try different drivers myself?

I see you have some braces in the horn path. Are they double braces, like the baffle, or just single braces in the middle?

Thanks,

This one is ok for the MTH-4654: [Vous devez être inscrit et connecté pour voir ce lien]

It has the same exact curve on 4 cabinets than the 18G401, and a more linear response on one cabinet compared to 18G401.

With the 21", you win:
- more sound level (more power in a 21")
- less distorsion at high power (less excursion in a 21")

You can win +3dB with a 21", but you will not goes lower or better sensitivity.

The braces are single braces. The double braces is just in front of the speaker to consolidate the speaker panel.

The height is 60cm external, 56.4cm internal, it's in the PDF

Hi Marc,

Thanks for the info. I see the RCF LF18N401 is a very similar driver to the 18G401, is the sim any different or is the neo version any better apart from weight? The neo handles more power so maybe more max SPL?
What's the max expected SPL in this box with these drivers?

Thanks again,

The 18N401 could be used with a similar response. You won't gain a lot. I recommend no more than 700 watts on the G401 and 900 watts on the 18N401, that's just 1 dB difference.

theorical SPL 133dB one cabinet at 900 watts,
142 dB 4 cabinets

Hi Marc,

Why only 900w into the LF18n401, is it because of excursion? If its replaced with 21LW1400 what power could that combination take? I saw you said earlier its about 3dB more than an 18", so 135dB/ box or something?

Thanks

yes, 18N401 limited power because of excursion and because AES is not a severe standard about power.

A 21" is not limited by excursion, because it has more cone surface and generally have a better X-max than a 18", and can handle more power.

Hi Marc,

Do you know what SPL the 21LW1400 could acheive? Woulld the 21NLW9600 neo version be suited to this box? The box is quite big so I want to get maximum performance for the size. I am thinking of building two cabinets to test, with perhaps eight in total if testing goes well.
Is it possible to see the HR data so I can model some drivers myself, without asking too much from you? 18Sound and RCF aren't cheap in the UK!

Thanks!

The box is quite big so I want to get maximum performance for the size

Yes it is big, but, if you want infra with good sensitivity, you can not have a little box, it's physically impossible.

If I take example of the SBH, it can not be used in single (or at detriment of low sensitivity below 60Hz). It works best on a stack of 8 cabinets or more. And if I make the comparison of 8 SBH (in grey) vs 8 MTH-4654 (in black), you will see who is the winner. and the MTH-4654 is a little less volume than the SBH, and can be used in signle. So I think it's a good compromise.

[Vous devez être inscrit et connecté pour voir cette image]

Most 21" have the same curve and sensitivity than a 18" in the MTH-4654, so the gain is the power only. For the 21LW1400 you gain 2 more dB than a 18N401.

Hi Marc,

Yes, it looks like a really good box. I really like the low group delay and bass extension.
Do you know roughly how much this box will weigh without a driver?
And is there any advantage with the 21NLW9600 over the 21LW1400?

Thanks again,

the 21LW9600 will goes 2/3 Hz lower, but with a lower sensitivity of 1 or 1.5dB. You win on one part but loose on other. It's like that on all designs.

For the weight, depend on the wood you use. Find the cubic volumic mass of the wood you choose, calc surface of the panels of the cabinet, then the cubic volume used by the cabinet.

any chance for HR inputs Marc? thank you

Hi Marc,

I've decided to get 2 MTH4564 built, using the 21LW1400. Can I just confirm to fit these drivers, we just need to make the hole in the baffle bigger and make the braces on the baffle smaller so they don't foul the cone area? Are there any other modifications you would carry out to the box for this driver?

Thanks!

yes it is just like that. There isn't any others modifications

[Vous devez être inscrit et connecté pour voir cette image]could you please sim some eminence or selenium drivers? thanks for the cool design!

What driver?

MTH-4654 has been tested by Venture with 21LW1400. He compared with F218. What he said:

"I did some intial testing on the MTH4654. I love it! I was comparing the sound quality and output to our F218 cabinets, and although its not quite as sensitive (as I expected) the sound is really really nice. The F218 has a harder kick and the transient response seems a little quicker which I also expected, but the frequency response seems a lot less peaky than the F218, you can hear all the different bass notes clearly as they go up and down and the sub sounds much cleaner (perhaps less distorted) than the F218. Also, even with one cab you can easily hear how much lower it goes. I tried one box driven from a Crown IT8000 and I was managing to set off car alarms outside the building (I was inside)!
As far as the box goes, there's no rattling/ chuffing so the bracing looks perfect. I had to leave the workshop early last night so I didn't have time to take any pictures, but I will send you some soon, the 21LW1400 looks like a monster in this box! I also had some grills made and will send you pictures when its all complete.

My plan is to have another six of the MTH made in the new year. For information, I was crossing the cab at 120Hz and there was no honking or distortion from it. I may try 100Hz in the future, to give a little more kick from the top boxes.

But I gotta say, what a great cabinet, thank you so much for the design! "

[Vous devez être inscrit et connecté pour voir cette image]

[quote="Marc34"]What driver?

MTH-4654 has been tested by Venture with 21LW1400. He compared with F218. What he said:

"I did some intial testing on the MTH4654. I love it! I was comparing the sound quality and output to our F218 cabinets, and although its not quite as sensitive (as I expected) the sound is really really nice. The F218 has a harder kick and the transient response seems a little quicker which I also expected, but the frequency response seems a lot less peaky than the F218, you can hear all the different bass notes clearly as they go up and down and the sub sounds much cleaner (perhaps less distorted) than the F218. Also, even with one cab you can easily hear how much lower it goes. I tried one box driven from a Crown IT8000 and I was managing to set off car alarms outside the building (I was inside)!
As far as the box goes, there's no rattling/ chuffing so the bracing looks perfect. I had to leave the workshop early last night so I didn't have time to take any pictures, but I will send you some soon, the 21LW1400 looks like a monster in this box! I also had some grills made and will send you pictures when its all complete.

My plan is to have another six of the MTH made in the new year. For information, I was crossing the cab at 120Hz and there was no honking or distortion from it. I may try 100Hz in the future, to give a little more kick from the top boxes.

But I gotta say, what a great cabinet, thank you so much for the design! "

[Vous devez être inscrit et connecté pour voir cette image][/quoteSpecifications:

ZXP-18

Voice Coil Diameter

5 "VC

Magnet Weight

2x120oz

Resonant Frequency (fs) Hz

25 Hz

Usable Frequency Range

25Hz-2KHz

Sensitivity

97 dB

Nominal Impedance (Re) ohms

8 ohm

DC Resistance

8.9

Coil Inductance (Le) mH

2.3

Mechanical Q (Qms)

8.32

Electrical Factor(Qes)

0.3

Total Q (Qts)

0.29

Comp. Equivalent Vol. (Vas)

545.7liters/18.6 cu.ft

Voice Coil Overhang (Xmax) mm

5.3

Surface Area of Cone (Sd) cm2

1143.5

Overall Diameter

463mm

Mounting Holes B.C.D.

442mm

Material

Die cast Aluminum chassis

the one above just tried and it is awesome...like a full blown fan boat!!!!!!
i had the eminence sigma pro 18 in it before and it sounded cleaner, but almost identical in driverack settins ...high pass at 35 hz , and low pass at 120 hz insane amount of bass...had a 80z low pas before and was not as loud, but definitely plays the lows
these are both cheap drivers and sound great! GREAT BOX MAN!