Tapped horn little project

[miniac007]

Hello,

I am starting a new project with a little tapped horn based on this one: Bass mit 10Zoll Tapped Horn - HiFi Forum

The driver is now unavailable, so I planed to use this one: SPA-10PA

I played a little with hornresp and i get this:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Any advice or suggestion are welcome !

 

[TundraLTD]

looks like you run out of excursion around 17 watts

 

[miniac007]

Hi TundraLDT,

you pointed it out !

The limit seems to be 16W for 117 db SPL.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

So is it a problem for a TH for HT in a 25m2 = 280sqft room (listening distance at 2.8m = 9.5 ft ? Do I need much ? Or what should I do to improve that ?

Is a class T amp of 20W will be a good solution to drive it thru a miniDSP for pass band filter ?

 

[Xoc1]

As long as you use a hi pass filter I would at least double that power rating for the amplifer.
Dependent on the driver and how it behaves when pushed past Xmax you could probably use even more.
Hornresp does not take into account any thermal compression in the driver.
You dont want the amplifier to clip as you get towards Xmax.

 

[miniac007]

Ok thanks.

I have a old Marrantz PM43, 30 watts x 2 at 8 ohms to test it. But after I'd like to get a little one. What do you think of Gainclone LM3886 based amp for this usage ?

 

[Juhazi]

The response starts at 30Hz and huge cone movement below it. I would not use this as a subwoofer for HT! At least you must be careful with power.

 

[miniac007]

I will have a high pass filter to cut at 30Hz. I want to test TH, and it is the best price/qualty 21" driver I found easily available with flat response and that reach 30Hz to 100Hz. 50€ = 65 $.

Do you know other low cost drivers which perform well down to 30 Hz in TH ?

 

[OscarS]

seems a bit high for a HPF here. The response will be cut starting just slightly above what you set it at, so in this case, I'd do a 25Hz HPF so it doesn't affect the low-30Hz response too much.

 

[miniac007]

Ok thanks !

 

[bjorno]

A Monacor SPA10PA TH that can be stuffed

Hi,

IMO, (After doing a math check.. the first one done here?): You need at least a BW 4 HPF at ~32 Hz; or a LR4 just below 30Hz to preserve a use of maximum available cone excursion before x-max limits the possible BW.

b

 

[tinitus]

really fine and cool looking driver
and I have been tempted myself, many times

but try ask yourself why its got such weird high Qts ?

hello Bjorn, nice to see you are still kicking, and havent broken all your bones from snowboarding

 

[miniac007]

Hello Bjorn, very nice Math ! Thank you very much.

I want to ask you which kind of response curve will perform better, n°1 or n° 4 ?

N°4 is flatty, little more SPL, but N°1 goes lower. Which will be the best for HT tapped horn ?


@Tinitus: "but try ask yourself why its got such weird high Qts ?" Lower Qts == higher prices

 

[miniac007]

Hi all,

I have an other question about the horn building: I want to have a side opened mouth like DTS-10, but I don't understand in this case how to measure L34 and S4:

An externally hosted image should be here but it was not working when we last tested it.

- Is S4 always the end of the section (S4-2) or is it the area of the aperture (S4-1) ?

- How to measure L34:

* Begining of the aperture L34-1 ?
* Axis of the aperture L34-2 ?
* End of the aperture L34-3 ?
* Always the end of the section L34-4 ?

Thanks !