10-30-2008, 05:16 AM
***This is just a skeleton build log for now, the review will be up in a day or so***
Tweeters came in...
MDF cut for boxes
Boxes all clamped up
Solid shell (Top, Back, and Sides)
Seas ER18’s arrived
Precision Port 2” for F3 of 58Hz
10-30-2008, 05:17 AM
Baffles cut and clamped
Almost ready for drivers!
Completed bookshelves :)
Their new home
11-09-2008, 03:05 AM
*** Well I know it's been more than a "day or so", but a lot of school work hit me at once, but here's most of my review, only thing left is the listening impressions, which I'm finishing up now ***
The tweeters come very securely nestled in a small, but appropriately sized box. Though the possibility still exists for UPS to harm your precious $200 set, there seems to be enough cardboard and packing foam between all the components to keep them safe. The information on the outside of the box is slightly confusing, however. The frequency response on the box is stated as 3Khz - 20Khz, which the frequency response on the TBI website is stated as 2Khz - 20Khz. This is a minor detail, but still raises the question, "what is the true frequency response?", which one can only find out by evaluating the FR plot on the website. "So what all comes in the box?", you might ask.
- 2x TBI HDSS Tweeters
- 2x Flush mounting cups
- 2x Angle mounting cups
- 2x Tweeter cups
- 2x TBI-engineered passive crossover (3.5Khz @ -6dB/octave)
- Miscellaneous mounting hardware (bolts, nuts, sticky mounts)
Upon first sight, these tweets are quite attractive! Of course surface mount users might complain about the large, bright "TBI - HDSS" printed on the face, but I paid no attention to it in my installation. I'm fairly sure the sugar cube trick would also suffice in removing the labeling if it really bothers you. The HDSS's are very heavy for their size, which to me, is a good indication of their build quality. All seams are smooth, there is no excess glue, and the product is overall very solid in look and feel. One thing I did notice while fiddling with the tweeters and mounting hardware is the the fitment between tweeters and tweeter cups is ungodly tight. Once you push the tweeter itself completely into the cup, it will almost never come out. While this may desirable in a mobile-environment, it makes for quite a difficult test fitting if you're one of those "measure twice, cut once" builders (which I happen to be).
Even though these tweeters are considered "mobile audio" drivers, I did not have the liberty of utilizing them in my car with my 2-channel amp since I could not run them actively. So I decided that I could use a new set of bookshelf speakers in my dorm room and then when I move to an active setup in my car, just transfer the components over. After much research into what to pair the TBI's with, I finally settled on the Seas ER18RNX 7" Midbasses. They're normally $70/each plus shipping from Madisound, but I got a BNIB pair from a member of caraudio.com for $120 shipped! An offer that good couldn't be passed up, so my design process around the ER18's and TWEP51's began. At the suggestion of Madisound, I decided on a .5 ft^3 box with a 6" long, 2" diameter flared port for an F3 of 58Hz. The following pictures illustrate my build. From final design to final product, total time on the build was approximately 15 hours, spread over two weekends since I'm a full-time student.
System Setup and Components:
So you already know about the boxes and the drivers, but what about the source and the amplification? All music and test materials will be played through my laptop with the stock, Realtek HD Audio card utilizing Winamp as my media library and the Enhancer .17 DSP plug-in. Amplification is provided by a quarter-century old Kenwood KR-950 Stereo Receiver. Though old, the KR-950 was the flagship of Kenwood's line during its time. Output is rated at 125wRMS @ 8 ohms per channel (this thing is a beast of an amp). Since this project was quite sudden and budget-oriented, the TWEP51's were ran with their supplied crossover (3.5Khz, -6dB/oct) and the Seas ER18's were ran UNTOUCHED. I think it's important to take note of that because the review is based on a system without any type of low pass or high pass filter on the mids (their frequency range as listed by Seas is 45Hz - 3KHz). So since I didn't invest in a set of crossovers, I faced the dilemma of having four channels needing power for two bookshelves. In addition, the tweeters having an impedance of 4 ohms and the ER18's having an impedance of 8 ohms seemed to cause some issues with my amplifier. Trying to run the mids on speaker set A and the tweets on speaker set B made the set sound awful! I believe this was due to the imbalance between the loads on the separate channels, however, after a little tinkering around, I just decided to twist the positive and negative from the tweeters and mids on both speakers and run them off a single channel. The results were outstanding!