my first ml tqwt

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I just have made my very first mass loaded tqwt with monacor sph-60x.The sound is great.Although we planned to make it two way,we'll maybe leave it as FR because it sounds great even without tweeter.I'll post pics later today.
Special thanks to MJK,I wouldn't have made it if it wasn't for his workshhets :)
 
Until you get the pics perhaps you could provide some details.

Is this folded or full pipe?
What is the line length?

I saw others had made very tall cabinets with a side vent and the top end was brought to a point.
 

Attachments

  • tqwt32.jpg
    tqwt32.jpg
    72.5 KB · Views: 930
Hi there, Tim! I'm glad to see somebody is interested in my project.
The pipe is folded.Line length is 192 cm.It tapers from 1 Sd at the beggining to 7 Sd at the end.Port is located 5 cm from the floor,r=3 cm,L=1.8 cm.Haven't stuffed it yet,but the sound of the unstuffed pipe without BSC is suprisingly good.Judging by the sim F3 point is somewhere round 40 Hz.I don't have measuring equipment so I can't analyze it...sure it has bass but it isn't a real punchy bass,although is not weak or lean.double bass sounds great on it,even some electronic music sound good on it,but it's not just bass heavy.I would say that it's more than enough bass for such a small driver.Previously I made BR box with same drivers and overall sound was not so good,it lacked treble and the bass wasn't so well defined.Changing the box to Tqwt improved both ends of spectrum.Ok, I expected that the bass will improve but the amount of treble I gained, suprised me a lot.Anyone has an idea how could one explain such an improvement in high range?
I'll continue my work on ML TQWT with fullrange drivers.Next will be Monacor Sp 200x and after that I dunno.I'll try to get some Fostex maybe?
Tommorrow I'll be adding a BSC circuit and damping the box.Any suggestions about damping?
 
I could guess and say that proper positioning of the driver will help counteract upper mid resonances providing a better overall sound, something more difficult to accomplish in a BR. I enjoy my RS 40-1197 bipole ML-TQWT. Placing another driver firing to the rear in phase with the forward driver helps the low end response by increasing Sd and providing baffle step compensation. It also helps rid the box sound. Full rangers may not provide the in-your-face experience of multi-way systems but they are very enjoyable to listen to.
 

GM

Member
Joined 2003
>Previously I made BR box with same drivers and overall sound was not so good,it lacked treble and the bass wasn't so well defined.Changing the box to Tqwt improved both ends of spectrum.Ok, I expected that the bass will improve but the amount of treble I gained, suprised me a lot.Anyone has an idea how could one explain such an improvement in high range?

====

Well, of course you didn't actually gain any treble, but from your comments I imagine you made an underdamped (boomy, or ringing) cab that 'drowned out' the treble somewhat. IOW poor tonal balance from lows to highs.

====

>I'll continue my work on ML TQWT with fullrange drivers.Next will be Monacor Sp 200x and after that I dunno.I'll try to get some Fostex maybe?
Tommorrow I'll be adding a BSC circuit and damping the box.Any suggestions about damping?

====

You don't say, but assuming you put the driver at the midpoint, then 0.4lbs/ft^3 looks good, with a small amount at the bottom to finish damping the peaking at Fb.

FWIW, if you are interested in experimenting more with this driver, a much shorter straight pipe yields audibly more efficiency down to ~55Hz, where it rolls off to ~4dB/40Hz lower than yours after damping and probably will not need any BSC.

GM
 
Hi,

Nice to hear that someone else have experienced the ML TQWT. IMO. TQWT do really have a real advantage. It makes a decent and simple driver to perform and outshine many other speaker system.

I am using the Brines FT16000 design using the Fostex 167E. The mids is phenomenal to say the least. I cannot afford a Lowther, but this is the closest that I can get with much more on the low end and the uppper end.

What I like best is the disappearing act of the speakers. No matter how bad is the CD recording, the image stays sharp and 3D.

Tell us more of your experience with ML TQWT. I am now searching to improve the low end. After listening to the direct connection, adding a BSC makes me feel like I need a tweeter to clean up some translucent veil in front of me.

Anyone any idea other than building a sub?

Thanks
 
Yes, I forgot, the driver is on the midpoint.Thanks for the suggestion to do the straight pipe and for the stuffing.I'll try the stuffing today but I'm not sure if I want to do another box, cause I'm pretty satisfied with this one and it has enough bass for me .Although it would be less trouble to do the straight line now it's too late to change it and it isn't really neccessary and after all I'm satisfied with their sound.
Classical music and jazz sound great on this speakers.Reggae sounds pretty decent.Of course they don't give much detail,but imaging is great and they sound very musical.And all that is without stuffing and baffle step compensation.I'll move them from the friends workplace to my home today to test them fully with different sorts of music and with different amounts of stuffing.I'll report you on results.;)
 
>Yes, I forgot, the driver is on the midpoint.Thanks for the suggestion to do the straight pipe and for the stuffing.I'll try the stuffing today but I'm not sure if I want to do another box, cause I'm pretty satisfied with this one and it has enough bass for me .Although it would be less trouble to do the straight line now it's too late to change it and it isn't really neccessary and after all I'm satisfied with their sound.

====

If the sim is accurate, then once you damp down the huge peaks it won't sound nearly as satisfying.

====

>Classical music and jazz sound great on this speakers.Reggae sounds pretty decent.Of course they don't give much detail,but imaging is great and they sound very musical.

====

Not familiar with this driver, but once you damp any 'ringing', it should help clarity/detail some.

====

>I'll report you on results

====

Looking forward to it!

GM
 
progression

OK here are the news about my ML TQWTs.I've added stuffing in both of them and made BSC circuit for 'em.I was suprised how the BSC improved overall sound. I have a pretty narrow baffle (17cm) so the loss was happening pretty high.Finnally,they're at my home and I gave good listening to them.The sound is just great.There is a obvious lack in upper highrange but that can be easily solved by adding a tweeter.Imaging is great,the soundstage is wide as wide it could be,it has height and depth,and there isn't any lack of detail that I could have noticed.Even the bass is preety deep and good defined.Ok,I did model them to play deep but I wasn't sure what to expect because this was my first ml tqwt design and first project that I made completely on my own (I did some kit previously).I'll be adding a tweeter for sure.I'm thinking about Monacor DT-119 in 1st order.I'll add pictures soon.

;)
tomac
 
FWIW, if you are interested in experimenting more with this driver, a much shorter straight pipe yields audibly more efficiency down to ~55Hz, where it rolls off to ~4dB/40Hz lower than yours after damping and probably will not need any BSC.

I'm glad you're enjoying your Voigt pipe. They can be very easy on the ears. I would encourage you to try a mechanical solution to baffle step. My choice was to use a rear-firing driver but GM's suggestion is intriguing.
 
It's just resistor and inductor connected in paralel.Shouldn't the goal of adding a BSC be attenuating the mid and high range?I don't really understand your question.Anyway,they sound balanced,but I'll measure their SPL soon with and without BSC so placebo effect will be avoided
cheers ;)
tomac
 
You probably ment that upper higrange lack is due to BSC? I'm not talking about it.I was thinking of adding a tweeter because of limitations of driver itself.That lack oh HF is obvious with and without BSC.Just a nature of a FR driver.To put it in other words-I'll be adding a supertweeter;)
cheers
Tomac:)
 
Not the HF if it was attenuated to begin with. We are discussing relative SPL relationships. Adding a cap in parallel allows the HF to bypass being rolled off, yielding a flatter response overall over a wider BW that often yields enough HF EQ that a tweeter is not required. That may not be the case here, but there is only one way to find out. ;) Note that this assumes you added a zobel across the driver as part of the BSC ckt..

GM
 
How should I determine the value of that capacitor? I both tried using BSC with and without Zobel.Version with Zobel has less treble (ofcourse).Haven't gave good listen to compare but in a short comparison the version without Zobel sounded better (which can be easily explained).I know that using BSC without Zobel isn't theoretically the most right decision one speakerbuilder could make but I think it gives a good result based on bad premises:D .Now I would like to add that capacitor to hear how would the correct circuit sound.
cheers
tomac
;)
 
Without measuring the FR with/without the zoebel, all you can do is try different cap values. With the zoebel in place, FR drivers typically require anywhere from 0.1uf - 3uf, so I start in 1uf increments depending on the driver's natural FR/amount of BSC/the room's HF absorption, then half, etc., till it sounds 'right' in-room/listening position. The values should be much smaller with no zoebel, but without an impedance plot I don't have a clue what the range would be.

Anyway, good luck with it and please let us know what you wind up with and whether or not it gets the job done. Some folk's HF hearing is keen enough (especially women/children) that only a high quality super tweeter will do, but experimenting with caps is cheap and you usually learn some things in the process.

GM
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.